В10 GOST 10705 80 transcript. Electric-welded steel pipes. Marking, packaging, transportation and storage

Diameter from 10 to 530 mm made of carbon and low-alloy steel, used for pipelines and structures for various purposes, except for pipes used for the manufacture of heat and electric heaters, are manufactured in accordance with GOST 10705-80.

Depending on the quality indicators, the pipes are manufactured in the following groups:

A - with standardization of mechanical properties from calm, semi-calm and boiling steel grades St1, St2, St3, St4 in accordance with GOST 380 (category 4 in accordance with GOST 16523, category 1 in accordance with GOST 14637);
B - with standardization of the chemical composition from calm semi-calm and boiling steel grades St1, St2, St3, St4 according to GOST 380 and GOST 14637, from calm, semi-calm and boiling steel grades 0.8, 10, 15 and 20 according to GOST 1050, from steel 08Yu grade in accordance with GOST 9045, from 22GYu grade low-alloy steel with the chemical composition given in the table (pipes with a diameter of 140 to 426 mm);
B - by rationing the mechanical properties and chemical composition of calm, semi-calm and boiling steel grades St1, St2, St3, St4 in accordance with GOST 380 (category 4 in accordance with GOST 16523 and category 2-5 in accordance with GOST 14637), thermally treated in a protective atmosphere. Pipes made of steel grade 22GYu are manufactured thermally treated along the welded joint or throughout the entire volume, pipes made of steel grade St1 - without heat treatment.

Table 1. The chemical composition of steel grade 22GYu (GOST 10705-80).

The mechanical properties of the base metal of pipes with a diameter of 10 to 152 mm, inclusive, without heat treatment and with heat treatment of the welded joint must comply with the standards specified in Table 2.

Table 2. Mechanical properties of the base metal of heat-treated and hot-rolled carbon steel pipes (GOST 10705-80)

steel grade	Ultimate resistance, N / mm2 (kgf / mm2)		Relative extension, %
steel grade	not less
08U	255 (26)	174 (18)	30
08kp	294 (30)	174 (18)	27
08, 08ps, 10kp	314 (32)	196 (20)	24
10, 10ps, 15kp, St2sp, St2ps, St2kp	333 (34)	206 (21)	24
15, 15ps, 20kp, St3sp, St3ps, St3kp	372 (38)	225 (23)	22
20, 20ps, St4sp, St4ps, St4kp	412 (42)	245 (25)	21

Note.

Table 3. Mechanical properties of the base metal of pipes with a diameter of 10 to 152 mm inclusive without heat treatment and with heat treatment of the welded joint (GOST 10705-80)

steel grade	Ultimate tensile strength, N / mm2 (kgf / mm2), with the outer diameter of pipes, D, mm, not less
	from 10 to 19	St. 19 to 60	St. 60 to 152
08U	314 (32)	294 (30)	264 (27)
08ps, 08kp	372 (38)	314(32)	294 (30)
St1ps, St1kp, 08, St1sp
10kp, St2kp		333(34)	314 (32)
10ps, St2ps	371 (38)
10, St2sp	372 (38)
15kp	441 (45)	372 (38)	353 (36)
15ps, 20kp
15, 20ps
20
St3kp		392 (40)	372 (38)
St3ps
St3sp
St4kp, St4ps	490 (50)	431 (44)	412 (42)
St4sp
22GU	-	-	490 (50)

Note.

At the request of the consumer, pipes with a wall thickness of 4 mm or more are manufactured:

from steel grades St3sp, 15, 15ps - with a yield point of 235 N / mm2 (24 kgf / mm2), a relative elongation of 23%;
from steel grades St4sp, 20, 20ps - with a yield point of 255 N / mm2 (26 kgf / mm2), a relative elongation of 22%;

Table 4. Mechanical properties of the base metal of pipes with a diameter of 10 to 152 mm inclusive without heat treatment and with heat treatment of the welded joint (GOST 10705-80)

steel grade	Yield strength, N / mm2 (kgf / mm2)
		from 10 to 60		St. 60 to 152
		more than 0.06 D	0.06 D and less
08U	176 (18)	7	16	25
08ps, 08kp		6	15	23
St1ps, St1kp, 08, St1sp	186 (19)
10kp, St2kp	176 (18)
10ps, St2ps	186 (19)
10, St2sp	196 (20)
15kp	186 (19)	5	14	21
15ps, 20kp	196 (20)
15, 20ps	206 (21)
20	216 (22)
St3kp	196 (20)		13	20
St3ps	206 (21)
St3sp	216 (22)
St4kp, St4ps		4	11	19
St4sp	225 (23)
22GU	344 (35)	-	-	15

Note. At the request of the consumer, for pipes of all steel grades with a diameter of 10 to 60 mm, the relative elongation increases by 3% in comparison with the standards given in the table.

Table 4. Mechanical properties of the base metal of pipes with a diameter of over 152 to 530 mm inclusive without heat treatment of the welded joint (GOST 10705-80)

steel grade	Wall thickness, mm	Yield strength, N / mm2 (kgf / mm2)	Elongation,%, with the outer diameter of pipes, D, mm
	Wall thickness, mm	Yield strength, N / mm2 (kgf / mm2)	St. 152 to 244.5	St. 244.5 to 377	St. 377 to 530
	not less
08.08ps, 08kp	6 or less	-	18	20	20
10, 10ps, 10kp, St2kp	more than 6	196 (20)	15	15	16
St2sp, St2ps	6 or less	-	17	18	20
St2sp, St2ps	more than 6	-	14	14	15
15, 15ps, 15kp, 20, 20ps, 20kp	6 or less	216 (22)	17	18	20
15, 15ps, 15kp, 20, 20ps, 20kp	more than 6	216 (22)	14	14	15
St3sp, St3ps, St3kp	6 or less	216(22)	17	17	19
St3sp, St3ps, St3kp	more than 6	216(22)	14	14	14
St4sp, St4ps, St4kp	6 or less	225 (23)	15	17	18
St4sp, St4ps, St4kp	more than 6	225 (23)	11	12	13
22GU	all thicknesses	344 (35)	15	15	15

STATE STANDARD OF THE UNION OF SSR

ELECTRIC WELDED STEEL PIPES

TECHNICAL CONDITIONS

GOST 10705-80

Publishing house of standards

Moscow

STATE STANDARD OF THE UNION OF SSR

Date of introduction 01.01.82

This standard applies to steel longitudinal electric-welded pipes with a diameter of 10 to 530 mm from carbon and low-alloy steel, used for pipelines and structures for various purposes.

The standard does not apply to steel pipes used for the manufacture of electric heaters.

(Modified edition, Amendment No. 5).

1. VARIETY

1.1. Dimensions and maximum deviations of pipes must comply with GOST 10704-91

2. TECHNICAL REQUIREMENTS

2.1. Electric-welded steel pipes are manufactured in accordance with the requirements of this standard and according to technical regulations approved in the prescribed manner.

2.2. Depending on the quality indicators, the pipes are manufactured in the following groups:

A - with standardization of mechanical properties from calm, semi-calm and boiling steel grades St1, St2, St3, St4 in accordance with GOST 380-94 (category 4 in accordance with GOST 16523-89, category 4 in accordance with GOST 14637 -89);

B - with standardization of the chemical composition of calm, semi-calm and boiling steel grades St1 St2, St3, St4 in accordance with GOST 380-94 and GOST 14637 -89, from calm, semi-calm and boiling steel grades 08, 10, 15 and 20 according to GOST 1050-88, from steel grade 08Yu according to GOST 9045

В - with standardization of mechanical properties and chemical composition from calm, semi-calm and boiling steel grades St1, St2, St3, St4 in accordance with GOST 380-94 (category 4 in accordance with GOST 16523-89 and category 2-5 in accordance with GOST 14637 -89), from calm, semi-calm and boiling steel grades 08, 10, 15 and 20 in accordance with GOST 1050-88, from steel grade 08Yu in accordance with GOST 9045-93, from low-alloy steel grade 22GYu with the chemical composition given in (pipes with a diameter of 140 to 426 mm);

D - with standardization of the test hydraulic pressure.

(Changed edition, Amendment No. 4, Amendment No. 5).

2.3. Pipes are manufactured thermally treated (over the entire volume of the pipe or along the welded joint), hot-rolled and without heat treatment.

The type of heat treatment for the entire volume of the pipe is chosen by the manufacturer. By agreement between the manufacturer and the consumer, pipes are thermally treated in a protective atmosphere.

Pipes made of steel grade 22GYu are made heat-treated along the welded joint or throughout the entire volume, pipes made of steel grade St1 - without heat treatment.

2.4. The mechanical properties of the base metal of heat-treated and hot-rolled carbon steel pipes must comply with the standards specified in. The mechanical properties of heat-treated pipes made of steel grade 22GYu are established by agreement of the parties.

2.5. The mechanical properties of the base metal of pipes with a diameter of 10 to 152 mm inclusive without heat treatment and with heat treatment of the welded joint must comply with the standards specified in table. ... The mechanical properties of the base metal of pipes with a diameter of over 152 to 530 mm, inclusive, without heat treatment and with heat treatment of the welded joint must comply with the standards specified in Art.

2.6. ... Cracks, captivity, sunsets, flaws and risks are not allowed on the pipe surface.

Ripples, nicks, dents, small marks, a layer of scale and traces of stripping are allowed provided that they do not bring the wall thickness and pipe diameter beyond the maximum deviations. Displacement of edges up to 10% of the nominal wall thickness is allowed.

The surface of pipes thermally treated in a protective atmosphere must be free of scale. The presence of an oxide film is allowed.

Lack of penetration of the seams must be welded, the place of welding must be cleaned. By agreement with the consumer, on pipes with a diameter of 159 mm and more, in places where welds are repaired by welding, the displacement of the welded edges of no more than 20% of the nominal wall thickness and the height of the reinforcement bead no more than 2.5 mm are allowed.

Repair by welding the base metal of pipes is not allowed.

In the case of repairs by welding pipes that have undergone heat treatment, they are subjected to repeated heat treatment (respectively, over the entire volume or along the welded joint).

(Changed edition, Amendment No. 1, Amendment No. 4, Amendment No. 5).

2.7. For pipes with a diameter of 57 mm and more, one transverse seam is allowed.

By agreement between the manufacturer and the consumer, one transverse seam is allowed on pipes with a diameter of less than 57 mm.

2.8. Outer burrs on pipes must be removed. In the place of deburring, the wall thinning by 0.1 mm above the minus tolerance is allowed.

At the request of the consumer, on pipes with an inner diameter of 33 mm and more, the inner burr must be partially removed or flattened, while the height of the burr or its traces should not exceed 0.35 mm - with a wall thickness of less than 2 mm; 0.4 mm - with a wall thickness of 2 to 3 mm; 0.5 mm - with a wall thickness of over 3 mm.

The height of the internal burr or its traces for pipes with an inner diameter of less than 33 mm is established by agreement between the manufacturer and the consumer.

(Modified edition, Amendments No. 1, 3).

2.9. The ends of the pipes should be cut at right angles and deburred. Chamfering is allowed. The slant of the cut for pipes with a diameter of up to 219 mm should not exceed 1 mm, and for pipes with a diameter of 219 mm and more - 1.5 mm. By agreement between the manufacturer and the consumer, the pipes are made cut in the mill line.

2.10. At the request of the consumer, at the ends of pipes with a wall thickness of 5 mm or more, a chamfer must be removed at an angle of 25-30 ° to the end of the pipe and an end ring with a width of 1.8 mm must be left± 0.8 mm. By agreement between the manufacturer and the consumer, the bevel angle and the width of the end ring can be changed.

2.11. The pipes must withstand the hydraulic test pressure. Depending on the value of the test pressure, pipes are divided into two types:

I - pipes up to 102 mm in diameter - test pressure 6.0 MPa (60 kgf / cm2) and pipes with a diameter of 102 mm and more - test pressure 3.0 MPa (30 kgf / cm2);

II -pipes of groups A and B, supplied at the request of the consumer with a test hydraulic pressure calculated in accordance with GOST 3845-75, with an allowable stress equal to 90% of the standard yield strength for pipes of this steel grade, but not exceeding 20 MPa (200 kgf / cm 2).

(Changed edition, Amendment No. 3, Amendment No. 5).

2.12. Heat-treated pipes made of steels of grades St3sp, St3ps (categories 3-5), 10, 15 and 20 with a wall thickness of at least 6 mm must withstand the impact bending test of the base metal. In this case, the norms of impact strength must correspond to those specified in Art.

2.13. Heat-treated pipes with a diameter of up to 152 mm inclusive, pipes hot-rolled and without heat treatment with a diameter of more than 20 to 152 mm inclusive and a wall thickness of 0.06 Dн and less, as well as pipes with heat treatment of the welded joint must withstand the flattening test.

Flattening of heat-treated pipes should be carried out up to the distance between flattening planes H, mm, calculated by the formula

,(1)

where a- the coefficient for pipes made of steel grades 08Yu, 08kp, 8ps, 08, 10kp, St2kp is 0.09, and for pipes made of other steel grades is 0.08;

S is the nominal wall thickness, mm;

Dн is the nominal outer diameter of the pipe, mm.

Flattening of pipes without heat treatment should be carried out to a distance equal to 2/3 Dн. Flattening of pipes with heat treatment of the welded joint should be carried out to a distance equal to 1/2 Dn.

At the request of the consumer, flattening of heat-treated pipes with a diameter of over 152 to 530 mm should be carried out to a distance equal to 2/3 Dн.

(Changed edition of Amendment No. 1, Amendment No. 3, Amendment No. 4, Amendment No. 5).

2.14. Pipes up to 108 mm in diameter must withstand the expansion test.

Pipes without heat treatment with a diameter of up to 20 mm, as well as a diameter of 20-60 mm with a wall thickness of more than 0.06 DH are not tested for expansion.

Increased outer diameter of heat treated. pipes during distribution must comply with the standards specified in.

The increase in the outer diameter of pipes without heat treatment during expansion should be at least 6%.

At the request of the consumer, the increase in the outer diameter when distributing heat-treated pipes with a wall thickness of up to 4 mm made of steel grades 10kp, St2kp should be at least 12%.

(Modified edition, Amendments No. 1, 3, 4).

2.15. At the request of the consumer, the pipes must withstand the tests provided for in paragraphs. -

The tensile strength of a welded joint of pipes with a diameter of 219 to 530 mm that have undergone heat treatment throughout the pipe volume or heat treatment of the welded joint must comply with the standards specified in ... The tensile strength of a welded joint of pipes with a diameter of 50 to 203 mm that have undergone heat treatment but the entire volume of the pipe or heat treatment of the welded joint must be at least 0.9 of the standards specified in .

The tensile strength of a welded joint of pipes without heat treatment with a diameter of 50 mm and more must comply with the standards specified in table. and .

2.19. The pipes must be tight.

(Modified edition, Amendment No. 3).

3. RULES OF ACCEPTANCE

3.1. Pipes are accepted in batches. A batch must consist of pipes of the same size, one steel grade, one type of heat treatment and one manufacturing group, accompanied by one quality document, in accordance with GOST 10692-80

with the addition of the chemical composition of steel in accordance with the document on the quality of the manufacturer of the workpiece.

The number of pipes in a batch should be no more than, pcs:

1000 - with a diameter of up to 30 mm;

600 - with a diameter of St. 30 to 76 mm;

400 - with a diameter of St. 76 to 152 mm;

200 - with a diameter of St. 152 mm.

3.2. In case of disagreement in assessing the quality of the chemical composition, at least one pipe from the batch is taken for inspection.

3.3. Each pipe is subject to inspection of the dimensions and quality of the pipe surface. It is allowed to control dimensions and surfaces selectively on each batch with a one-stage normal level of control in accordance with the requirements of GOST 18242-72. Control plans are established by agreement between the manufacturer and the consumer.

(Modified edition, Amendment No. 3).

3.3a. Welded seams of pipes of groups A, B and C must be subjected to 100% non-destructive testing.

When carrying out non-destructive testing along the perimeter of the entire pipe, hydraulic testing of pipes of the type I allowed not to conduct.

Allowed instead of non-destructive testing of welded seams of pipes of the type I test each pipe with increased hydraulic pressure, calculated in accordance with the requirements of GOST 3845-75 at an allowable stress equal to 85% of the yield point for pipes with a diameter of 273 mm and more and 75% of the yield point for pipes with a diameter of less than 273 mm, but not exceeding 12 MPa (120 kgf / cm 2).

Group D pipes must be subjected to hydraulic pressure testing or non-destructive testing of the welded seam.

(Introduced additionally, Amendment No. 3). (Modified edition, Amendment No. 5). (Amendment,).

3.4. To check the height of the internal burr, 2% of the pipes from the batch are taken.

3.5. For flattening, expansion, beading, bending, impact strength, tendency of the base metal of pipes to mechanical aging, tension of the base metal and the weld, two pipes are taken from the batch.

The yield point of the base metal of the pipes is determined at the request of the consumer.

At the request of the consumer, the determination of the impact strength is not carried out.

Pipes subjected to the flattening test are not subjected to the expansion test.

(Modified edition, Amendment No. 1).

3.6. Upon receipt of unsatisfactory test results for at least one of the indicators for it, repeated tests are carried out on a double number of pipes selected from the same batch.

Retest results apply to the entire batch.

3.7. Places of welding seams of pipes of groups A, B, C should be checked by non-destructive methods, and the repaired pipes must be tested by hydraulic pressure in accordance with the requirements of paragraph 3.3a of this standard.

Places of welding seams of pipes of group D must be tested by non-destructive methods, or pipes after repair must be tested by hydraulic pressure.

(Introduced additionally, Amendment No. 1, Amended edition, Amendment No. 5).

4. TEST METHODS

4.1. For quality control, one sample is cut from each selected pipe for each type of test, and for testing for impact strength - three samples for each test temperature.

4.2. The chemical composition of steel is determined according to GOST 22536.0 -87; GOST 22536.1 -88; GOST 22536.2 -87; GOST 22536.3 -88; GOST 22536.4 -88; GOST 22536.5 -87; GOST 22536.6 -88 GOST 12344-88; GOST 12345-88; GOST 12346-78; GOST 12347-77, GOST 12348-78; GOST 12349-83; GOST 12350-78; GOST 12351 -81; GOST 12352-81; GOST 12353-78; GOST 12354-81. Samples for determining the chemical composition are taken in accordance with GOST 7565-81.

4.3. Inspection of the pipe surface is carried out visually. The depth of defects is checked by filing or in another way.

It is allowed to control the surface and dimensions of pipes by non-destructive methods according to technical documentation.

(Modified edition, Amendment No. 1).

4.4. Pipes measure:

length - with a tape measure but GOST 7502-89.

outer diameter and ovality - adjustable with a measuring bracket in accordance with GOST 2216-84 or a caliper in accordance with GOST 166-89 or a micrometer in accordance with GOST 6507-89 ;;

or a caliper in accordance with GOST 166-89, or a micrometer in accordance with GOST 6507-89;

inner diameter - with a plug in accordance with GOST 14810-69, or with a caliber in accordance with GOST 2015-84, or by subtracting two wall thicknesses from the outer diameter;

curvature - with a straight edge in accordance with GOST 8026-92 and a probe;

wall thickness, wall thickness and height of the internal burr - with a micrometer in accordance with GOST 6507 -90 or a wall gauge in accordance with GOST 11358-89;

displacement of the edges - with a template according to technical documentation or a micrometer according to GOST 6507-90 or a vernier depth gauge according to GOST 162-90;

oblique cut is provided by the design of the equipment for processing pipe ends, the bevel angle of the chamfer is provided by a goniometer in accordance with GOST 5378-88. In case of disagreement in assessing the quality, the oblique cut is checked with a coal miner and a probe;

the end ring at the ends of the pipes - with a ruler in accordance with GOST 427 -75;

the depth of surface defects - using a barbell depth gauge in accordance with GOST 162-90. The measurement of the outer diameter of the pipe is carried out at a distance of at least 15 mm from the end of the pipe for pipes with the ratio of the outer diameter to the wall thicknessD H / S H equal to 35 or less; at a distance of at least 2/3 D H -for pipes with an attitudeD H / S H over 35 to 75; at a distance of at least D H - for pipes with ratioD H / S H over 75.

(Modified edition, Amendments No. 1, 3).

4.5. Impact bending test is carried out on longitudinal specimens of type 3 according to GOST 9454-78 cut from a pipe section located at an angle of about 90 ° to the weld.

Impact strength is determined as the arithmetic mean value based on the test results of three samples. On one of the samples, a decrease in impact strength by 9.8 is allowed· 10 4 J / m2 (1 kgf · m / cm 2).

The temperature of the impact bending test of pipes made of steel grades 08, 10, 15 and 20 is chosen by the consumer.

(Modified edition, Amendment No. 1).

4.6. The tendency of the base metal of pipes to mechanical aging is determined in accordance with GOST 7268-82. Straightening of samples by static load is allowed.

4.7. The tensile test is carried out in accordance with GOST 10006-80 on a longitudinal (in the form of a strip or a pipe segment) proportional to a short sample.

When testing on samples of a segmented section, the latter is cut out from a section located at an angle of about 90 ° to the weld, and is not straightened in the calculated part.

Instead of tensile testing, it is allowed to control the ultimate strength, yield strength and relative elongation of pipes by non-destructive methods.

GOST 10705-80

INTERSTATE STANDARD

ELECTRIC WELDED STEEL PIPES

TECHNICAL CONDITIONS

Date of introduction 01.01.82

This standard applies to longitudinal electric-welded steel pipes with a diameter of 10 to 630 mm from carbon and low-alloy steels used for pipelines, structures, and products for various purposes.

The standard does not apply to steel pipes used for the manufacture of electric heaters.

1. VARIETY

1.1. The dimensions and maximum deviations of pipes must comply with GOST 10704.

2. TECHNICAL REQUIREMENTS

2.1. Electric-welded steel pipes are manufactured in accordance with the requirements of this standard and according to technical regulations approved in the prescribed manner.

2.2. Depending on the quality indicators, the pipes are manufactured in the following groups:

A - with standardization of mechanical properties from calm, semi-calm and boiling steel grades St1, St2, St3, St4 in accordance with GOST 380;

B - with the standardization of the chemical composition:

GOST 380;

GOST 1050;

From steel grade 08Yu in accordance with GOST 9045;

GOST 19281

B - with standardization of mechanical properties and chemical composition:

From calm, semi-calm and boiling steel grades St1, St2, St3, St4 in accordance with GOST 380;

From calm, semi-calm and boiling steel grades 08, 10, 15, 20 in accordance with GOST 1050;

From steel grade 08Yu in accordance with GOST 9045;

From low-alloy steel grade 22GYu with a chemical composition according to table 1a (pipes with a diameter of 114 to 630 mm inclusive);

From low-alloy steel grades in accordance with GOST 19281 and other regulatory documents with a standardized carbon equivalent of no more than 0.46% (pipes with a diameter from 114 to 630 mm incl.);

D - with standardization of the test hydraulic pressure.

Pipes are made from rolled products in accordance with GOST 14637 (categories 1 - 5), GOST 16523 (category 4), GOST 9045, GOST 19281 and other regulatory documents approved in the prescribed manner.

(Modified edition, Amendment No. 7)

Table 1a

Steel grade	Mass fraction of elements,%
		Manganese	Aluminum
				no more

Note. Permissible deviations for the mass fraction of elements from the norms given in the table must comply with GOST 19281

2.3. Pipes from carbon steel grades are manufactured thermally treated (throughout the pipe volume or along the welded joint), hot-rolled or without heat treatment. Pipes from steel grade St1 are made without heat treatment.

Pipes from low-alloy steel grades are made thermally treated (throughout the pipe volume or along a welded joint) or without heat treatment.

The type of heat treatment is chosen by the manufacturer. By agreement between the manufacturer and the customer, the pipes are thermally treated in a protective atmosphere.

2.2, 2.3 (New edition, Amendment No. 6).

2.4. The mechanical properties of the base metal of heat-treated and hot-rolled pipes of groups A and B made of carbon and low-alloy steels must comply with the standards specified in Art. The mechanical properties of the base metal of heat-treated pipes of groups A and B made of steel grade 22ГЮ are established by agreement between the manufacturer and the consumer.

steel grade	Elongation d 5,%	steel grade	Ultimate tensile strength s in, N / mm 2 (kgf / mm 2)	Yield strength s t N / mm 2 (kgf / mm 2)	Elongation d 5,%
steel grade		steel grade
		St4sp, St4ps,

08, 08ps, 10kp
10, 10ps, 15kp, St2sp, St2kp,		20F, 20-KSH, 06GB
20kp, St3ps, St3sp, St3kp		09G2S, 09GSF, 13HFA, 17GS, 17G1S, 17G1S-U, 08KhMFCHA, 22GF, 26KHMA

Note. At the request of the customer, pipes with a wall thickness of 4 mm or more from steel grades St3sp, 15, 15ps are manufactured with a yield point of 235 N / mm 2 (24 kgf / mm 2), a relative elongation of 23%; from steel grades St4sp, 20, 20ps - with a yield point of 255 N / mm 2 (26 kgf / mm 2), a relative elongation of 22%.

(Changed edition, Amendment No. 6,).

steel grade

Ultimate tensile strength s in, N / mm 2 (kgf / mm 2), with the outer diameter of pipes D, mm

Elongation d s,%, with the outer diameter of pipes D, mm

St. 19 to 60

St. 60 to 152

from 10 to 60 at wall thickness

St. 60 to 152

more than 0.06 D

0,06 D and less

St1ps, St1kp

10kp, St2kp

10ps, St2ps

St4kp, St4ps

20F, 20-KSH, 06GB

09G2S, 09GSF, 13HFA, 17GS, 17G1S, 17G1S-U, 08HMFCHA, 22GF, 26HMA

Note. At the request of the customer, for pipes of all steel grades with a diameter from 10 to 60 mm, the relative elongation increases by 3% in comparison with the standards given in.

steel grade	Wall thickness, mm	Ultimate tensile strength s in, N / mm 2 (kgf / mm 2),	Yield strength s t, N / mm 2 (kgf / mm 2)	Elongation d s,%, with the outer diameter of pipes D, mm
		Ultimate tensile strength s in, N / mm 2 (kgf / mm 2),	Yield strength s t, N / mm 2 (kgf / mm 2)	St. 152 to 244.5	St. 244.5 to 377	St. 377 to 630

08.08ps, 08kp
10, 10ps, 10kp, St2kp
St2sp, St2ps
St2sp, St2ps
15, 15ps, 15kp, 20, 20ps, 20kpp
15, 15ps, 15kp, 20, 20ps, 20kpp
St3sp, St3ps, St3kp
St3sp, St3ps, St3kp
St4sp, St4ps, St4kp
St4sp, St4ps, St4kp
	All thicknesses
20F, 20-KSH, 06GB	All thicknesses
09G2S, 09GSF, 13HFA, 13GS, 17GS, 17G1S, 17G1S-U, 08HMFCHA, 22GF, 26HMA	All thicknesses
	All thicknesses

(Modified edition, Amendment No. 7)

2.5. The mechanical properties of the base metal of pipes of groups A and B without heat treatment and with heat treatment of a welded joint with a diameter of 10 to 152 mm inclusive must comply with the standards specified in, with a diameter over 152 to 630 mm inclusive - the standards specified in Art.

2.6. Cracks, captivity, sunsets, flaws and risks are not allowed on the pipe surface.

The surface of pipes thermally treated in a protective atmosphere must be free of scale. The presence of an oxide film is allowed.

Lack of penetration of the seams must be welded, the place of welding must be cleaned. By agreement with the customer, on pipes with a diameter of 159 mm and more, in places where seams are repaired by welding, the displacement of the welded edges of no more than 20% of the nominal wall thickness and the height of the reinforcement bead no more than 2.5 mm are allowed.

Repair by welding the base metal of pipes is not allowed.

In the case of repairs by welding pipes that have undergone heat treatment, they are subjected to repeated heat treatment (respectively, over the entire volume or along the welded joint).

2.7. For pipes with a diameter of 57 mm and more, one transverse seam is allowed.

By agreement between the manufacturer and the customer, one transverse seam is allowed on pipes with a diameter of less than 57 mm.

2.6, 2.7.

2.8. Outer burrs on pipes must be removed. In the place of deburring, the wall thinning by 0.1 mm above the minus tolerance is allowed.

At the request of the customer, on pipes with an inner diameter of 33 mm and more, the inner burr must be partially removed or flattened, while the height of the burr or its traces should not exceed 0.35 mm - with a wall thickness of less than 2 mm; 0.4 mm - with a wall thickness of 2 to 3 mm; 0.5 mm - with a wall thickness of over 3 mm.

The height of the internal burr or its traces for pipes with an inner diameter of less than 33 mm is set by agreement between the manufacturer and the customer.

(Changed edition, Amendment No. 1,).

2.9. The ends of the pipes should be cut at right angles and deburred. Chamfering is allowed. The slant of the cut for pipes with a diameter of up to 219 mm should not exceed 1.0 mm, with a diameter of 219 to 426 mm inclusive - 1.5 mm, with a diameter of more than 426 mm - 2.0 mm. By agreement between the manufacturer and the customer, the pipes are made cut in the mill line.

2.10. At the request of the customer, the ends of pipes with a wall thickness of 5 mm or more must be chamfered at an angle of 25 - 30 ° to the end of the pipe and an end ring with a width of (1.8 ± 0.8) mm must be left. By agreement between the manufacturer and the customer, the bevel angle and the width of the end ring can be changed.

2.11. The pipes must withstand the hydraulic test pressure. Depending on the value of the test pressure, pipes are divided into two types:

I - pipes with a diameter of up to 102 mm - test pressure 6.0 MPa (60 kgf / cm 2) and pipes with a diameter of 102 mm and more - test pressure 3.0 MPa (30 kgf / cm 2);

II - pipes of groups A and B, supplied at the request of the customer with a test hydraulic pressure calculated in accordance with GOST 3845, with an allowable stress equal to 90% of the standard yield strength for pipes of this steel grade, but not exceeding 20 MPa (200 kgf / cm 2).

(Modified edition, Amendment No. 5).

2.12. Pipes heat-treated throughout the entire volume, groups A and B, with a wall thickness of at least 6 mm, made of steels of grades St3sp, St3ps (categories 3-5), 10, 15, 20 and low-alloy steels, must withstand impact bending tests of the base metal ... In this case, the norms of impact strength should correspond to those indicated in table. ... The impact bending test of the base metal of thermally treated pipes of groups A and B made of steel grade 22GYu is carried out at the request of the customer, the impact strength standards are set by agreement between the manufacturer and the customer.

2.13. Heat-treated pipes with a diameter of up to 152 mm inclusive, pipes hot-rolled and without heat treatment with a diameter of more than 20 to 152 mm inclusive and a wall thickness of 0.06D n and less, as well as pipes with heat treatment of the welded joint must withstand the flattening test.

Flattening of heat-treated pipes must be carried out up to the distance between flattening planes N, mm, calculated by the formula

where a- the coefficient for pipes made of steel grades 08Yu, 08kp, 8ps, 08, 10kp, St2kp is 0.09, and for pipes made of other steel grades is 0.08;

S- nominal wall thickness, mm;

D n - nominal outer diameter of the pipe, mm.

Flattening of pipes without heat treatment should be carried out to a distance equal to 2/3D H ... Flattening of pipes with heat treatment of the welded joint and hot-rolled pipes should be carried out to a distance of 1/2D H.

At the request of the customer, flattening of heat-treated pipes with a diameter of over 152 to 530 mm should be carried out to a distance equal to 2/3D n.

(Changed edition, Amendment No. 5,).

2.14. Pipes up to 108 mm in diameter must withstand the expansion test.

Pipes with a diameter of up to 108 mm made of carbon steel grades specified in table 5 must withstand the expansion test.

The increase in the outer diameter of heat-treated pipes during distribution must comply with the standards specified in.

The increase in the outer diameter of pipes without heat treatment during expansion should be at least 6%.

At the request of the customer, the increase in the outer diameter when distributing heat-treated pipes with a wall thickness of up to 4 mm made of steel grades 10kp, St2kp must be at least 12%.

(Changed edition, Amendment No. 1,, 4,).

2.15. At the request of the customer, pipes must withstand the tests provided for in paragraphs. -.

2.17. Heat-treated throughout the entire volume of carbon steel pipes with a diameter of 30 to 159 mm with a wall thickness of no more than 0.08Dmust withstand the airborne test. The amount of flanging must be at least 24%, while the width of the bend to be bent, measured from the inner surface of the pipe, must be at least 1.5 times the wall thickness of the pipe.

The flange angle should be:

90 ° - for pipes made of steel grades 08, 10, 15, St2;

60 ° - for pipes made of steel grades 20, St3, St4.

The ultimate strength of a welded joint of pipes without heat treatment with a diameter of 50 mm or more must comply with the standards specified in and.

(Changed edition, Amendment No. 1,,,).

2.19. The pipes must be tight.

(Modified edition, Amendment No. 3).

3. RULES OF ACCEPTANCE

3.1. Pipes are accepted in batches. A batch should consist of pipes of the same size, one steel grade, one type of heat treatment and one manufacturing group, accompanied by one quality document, in accordance with GOST 10692 with the addition of the chemical composition of steel in accordance with the document on the quality of the manufacturer of the workpiece.

The number of pipes in a batch should be no more than, pcs:

1000 - with a diameter of up to 30 mm;

600 - with a diameter of St. 30 to 76 mm;

400 - with a diameter of St. 76 to 152 mm;

200 - with a diameter of St. 152 mm.

(Modified edition, Amendment No. 1).

3.2. In case of disagreement in assessing the quality of the chemical composition, at least one pipe from the batch is taken for inspection.

3.3. Each pipe is subject to inspection of the dimensions and quality of the pipe surface. It is allowed to control dimensions and surfaces selectively on each batch with a one-stage normal level of control in accordance with the requirements of GOST 18242 *. Control plans are established by agreement between the manufacturer and the customer.

(Modified edition, Amendment No. 3).

* On the territory of the Russian Federation, GOST R 50779.71-99 ** is in force.

3.6. Upon receipt of unsatisfactory test results for at least one of the indicators for it, repeated tests are carried out on a double number of pipes selected from the same batch.

Retest results apply to the entire batch.

3.7. Places of welding seams of pipes of groups A, B, C must be inspected by non-destructive methods, and the repaired pipes must be tested with hydraulic pressure in accordance with the requirements of this standard.

Places of welding seams of pipes of group D must be tested by non-destructive methods, or pipes after repair must be tested by hydraulic pressure.

(Modified edition, Amendment No. 5).

4. TEST METHODS

4.1. For quality control, one sample is cut from each selected pipe for each type of test, and for testing for impact strength - three samples for each test temperature.

4.2. The chemical composition of steel is determined according to GOST 22536.0 - GOST 22536.6, GOST 12344 - GOST 12354. Samples for determining the chemical composition are taken in accordance with GOST 7565.

Metal carbon equivalent ( WITH e) low-alloy steel grades are calculated by the formula

where WITH, Mp, WITH r, Moe, V,Si, Ni- mass fraction of carbon, manganese, chromium, molybdenum, vanadium, copper, nickel in steel,%.

(Modified edition, Amendment No. 6).

4.3. Inspection of the pipe surface is carried out visually. The depth of defects is checked by filing or in another way.

It is allowed to control the surface and dimensions of pipes by non-destructive methods according to technical documentation.

(Modified edition, Amendment No. 1).

4.4. Pipes measure:

outer diameter and ovality - with an adjustable measuring bracket in accordance with GOST 2216 or a caliper in accordance with GOST 166, or a micrometer in accordance with GOST 6507;

inner diameter - with a plug in accordance with GOST 14810 or a caliber in accordance with GOST 2015, or by subtracting two wall thicknesses from the outer diameter;

curvature - with a straight edge in accordance with GOST 8026 and a probe;

wall thickness, wall thickness and height of the internal burr - with a micrometer in accordance with GOST 6507 or a wall gauge in accordance with GOST 11358;

displacement of the edges - with a template according to technical documentation or a micrometer according to GOST 6507 or a vernier depth gauge according to GOST 162;

oblique cut is provided by the design of the equipment for processing pipe ends, the bevel angle of the chamfer is provided by a goniometer in accordance with GOST 5378. In case of disagreement in assessing the quality, the oblique cut is checked with a coal miner and a probe;

the end ring at the ends of the pipes - with a ruler in accordance with GOST 427;

the depth of surface defects - using a vernier depth gauge in accordance with GOST 162. The measurement of the outer diameter of the pipe is carried out at a distance of at least 15 mm from the end of the pipe for pipes with the ratio of the outer diameter to the wall thicknessD n / S n equal to 35 or less; at a distance of at least 2/3D n - for pipes with the ratioD n / S n over 35 to 75; at a distance of at leastD n - for pipes with the ratioD n / S n over 75.

(Changed edition, Amendment No. 1,).

4.5. The impact bending test is carried out on longitudinal specimens of type 3 in accordance with GOST 9454, cut from a section of the pipe located at an angle of about 90 ° to the weld.

Impact strength is determined as the arithmetic mean value based on the test results of three samples. On one of the samples, a decrease in impact strength by 9.8 is allowed× 10 4 J / m 2 (1 kgf × m / cm 2).

The impact test temperature is specified by the purchaser in the pipe purchase order.

(Changed edition, Amendment No. 1,).

4.6. The tendency of the base metal of pipes to mechanical aging is determined in accordance with GOST 7268. Straightening of samples by static load is allowed.

4.7. The tensile test is carried out in accordance with GOST 10006 on a longitudinal proportional short sample.

When tested on specimens of a segmented section, the latter is cut from a section located at an angle of about 90 ° to the weld seam, and is not straightened in the calculated part.

Instead of tensile testing, it is allowed to control the ultimate strength, yield strength and relative elongation of pipes by non-destructive methods.

If disagreements arise, the pipes are tested in accordance with GOST 10006.

(Changed edition, Amendment No. 1,).

4.8. Flattening test is carried out according to GOST 8695.

4.9. The expansion test is carried out in accordance with GOST 8694 on a mandrel with a taper of 30 °. It is allowed to use mandrels with a taper of 1:10 and to remove burrs in the distribution area.

(Modified edition, Amendment No. 3).

4.10. The bend test is carried out in accordance with GOST 3728. Pipes with a diameter of 114 mm are tested on cut longitudinal strips 12 mm wide.

4.11. The test for boarding is carried out in accordance with GOST 8693. Burr removal is allowed on the flanging section.

4.12. The determination of the ultimate resistance of the welded joint is carried out on ring samples according to the technical documentation.

On pipes with a diameter of 219 mm and more, it is allowed to test in accordance with GOST 6996 on specimens of type XII with removed reinforcement of the welded joint, cut perpendicular to the pipe axis, using a static load when straightening the specimens.

(Modified edition, Amendment No. 7).

4.13. Hydraulic testing of pipes is carried out in accordance with GOST 3845 with holding under pressure of 5 s.

4.14. The control of the welded seam is carried out by non-destructive methods (ultrasonic, eddy current, magnetic or X-ray equivalent method) according to the technical documentation.

5. MARKING, PACKAGING, TRANSPORTATION AND STORAGE

5.1. Marking, packaging, transportation and storage - in accordance with GOST 10692.

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the Ministry of Ferrous Metallurgy of the USSR

2. APPROVED AND INTRODUCED INTO EFFECT by the Resolution of the USSR State Committee for Standards dated 25.12.80 No. 5970

Amendment No. 5 was adopted by the Interstate Council for Standardization, Metrology and Certification (Minutes No. 13 of May 28, 1998)

Registered by the IGU Technical Secretariat No. 3166

State name	Name of the national standardization body
The Republic of Azerbaijan	Azgosstandart
Republic of Armenia	Armgosstandart
Republic of Belarus	State Standard of the Republic of Belarus
The Republic of Kazakhstan	Gosstandart of the Republic of Kazakhstan
Republic of Kyrgyzstan	Kyrgyzstandard
The Republic of Moldova	Moldovastandart
The Russian Federation	Gosstandart of Russia

INTERSTATE STANDARD

ELECTRIC WELDED STEEL PIPES

TECHNICAL CONDITIONS

Official edition

Standardinform

UDC 669.14-462.2: 621.791.7: 006.354

Group B62

INTERSTATE STANDARD

ELECTRIC WELDED STEEL PIPES

Technical conditions

Electrically welded steel tubes. Specifications

ISS 23.040.10 OKP 13 7300 13 8100 13 8300

Date of introduction 01.01.82

This standard applies to steel longitudinal electric-welded pipes with a diameter of 10 to 530 mm from carbon and low-alloy steel, used for pipelines and structures for various purposes.

The standard does not apply to steel pipes used for the manufacture of heating electric heaters.

1. VARIETY

1.1. The dimensions and maximum deviations of pipes must comply with GOST 10704.

2. TECHNICAL REQUIREMENTS

2.1. Electric-welded steel pipes are manufactured in accordance with the requirements of this standard and according to technical regulations approved in the prescribed manner.

2.2. Depending on the quality indicators, the pipes are manufactured in the following groups:

A - with standardization of mechanical properties from calm, semi-calm and boiling steel grades St1, St2, StZ, St4 in accordance with GOST 380 (category 4 in accordance with GOST 16523, category 1 in accordance with GOST 14637);

B - with standardization of the chemical composition from calm, semi-calm and boiling steel grades St1, St2, StZ, St4 according to GOST 380 and GOST 14637, from calm, semi-calm and boiling steel grades 08, 10, 15 and 20 according to GOST 1050, from steel grade 08Yu in accordance with GOST 9045, from low-alloy steel grade 22GYu with the chemical composition given in table. 1a (pipes with a diameter of 140 to 426 mm);

B - with standardization of mechanical properties and chemical composition from calm, semi-calm and boiling steel grades St1, St2, StZ, St4 according to GOST 380 (category 4 according to GOST 16523 and categories 2-5 according to GOST 14637), from calm, semi-calm and boiling steel grades 08, 10, 15, 20 in accordance with GOST 1050, from steel 08Yu in accordance with GOST 9045, from low-alloy steel grade 22GYu with the chemical composition given in table. 1a (pipes with a diameter of 140 to 426 mm);

D - with standardization of the test hydraulic pressure.

2.3. Pipes are manufactured thermally treated (over the entire volume of the pipe or along the welded joint), hot-rolled and without heat treatment.

Pipes made of steel grade 22GYu are manufactured thermally treated along the welded joint or throughout the entire volume, pipes made of steel grade St1 - without heat treatment.

Official edition

Reprinting prohibited

Standards Publishing House, 1981 5) STANDARDINFORM, 2005 5) STANDARDINFORM, 2008

Table 1a

2.4. The mechanical properties of the base metal of heat-treated and hot-rolled carbon steel pipes must comply with the standards specified in table. 1. The mechanical properties of heat-treated pipes made of steel grade 22ГЮ are established by agreement of the parties.

Table 1

steel grade	steel grade	Ultimate tensile strength a b, N / mm 2 (kgf / mm 2)	Yield strength from t, N / mm 2 (kgf / mm 2)	Elongation 6 5,%
steel grade	steel grade

	20kp, StZsp,
08, 08ps, Yukp	StZps, StZkp
10, JUPS, 15kp,
St2sp, St2ps,	St4sp, St4ps,

Note. At the request of the consumer, pipes with a wall thickness of 4 mm or more from steel grades StZps, 15, 15ps are manufactured with a yield point of 235 N / mm 2 (24 kgf / mm 2), a relative elongation of 23%; from steel grades St4sp, 20, 20ps - with a yield point of 255 N / mm 2 (26 kgf / mm 2), a relative elongation of 22%.

table 2

	Ultimate tensile strength about in, N / mm 2, (kgf / mm 2), with the outer diameter of pipes D, mm			Yield strength from t, N / mm 2, (kgf / mm 2)	Elongation 6 5, pipe outer diameter D,		%>, at mm
steel grade					from 10 to 60 at wall thickness		St. 60 to 152
		St. 19 to 60	St. 60 to 152		more than 0.06 D	0.06 D and less	St. 60 to 152


St1ps, St1kp

Yukp, St2kp
Yups, St2ps








St4kp, St4ps

Note. At the request of the consumer, for pipes of all steel grades with a diameter of 10 to 60 mm, the relative elongation increases by 3% in comparison with the standards given in table. 2.

Table 3

steel grade	Thickness, walls, mm	Ultimate tensile strength a b, N / mm 2 (kgf / mm 2)	Yield strength with t, N / mm 2 (kgf / mm 2)	Elongation 6 5,%, with pipe diameter D, mm
		Ultimate tensile strength a b, N / mm 2 (kgf / mm 2)	Yield strength with t, N / mm 2 (kgf / mm 2)	St. 152 to 244.4	St. 244.5 to 377	St. 377 to 530

08, 08ps, 08kp
YUDOps, Yukp, St2kp
St2sp, St2ps
St2sp, St2ps
15, 15ps, 15kp, 20, 20ps, 20kp
15, 15ps, 15kp, 20, 20ps, 20kp
StZps, StZps, StZkp
StZps, StZps, StZkp
St4ps, St4ps, St4kp
St4ps, St4ps, St4kp
	All thicknesses

2.5. The mechanical properties of the base metal of pipes with a diameter of 10 to 152 mm inclusive without heat treatment and with heat treatment of the welded joint must comply with the standards specified in table. 2. The mechanical properties of the base metal of pipes with a diameter over 152 to 530 mm inclusive without heat treatment and with heat treatment of the welded joint must comply with the standards specified in table. 3.

2.6. Cracks, captivity, sunsets, flaws and risks are not allowed on the pipe surface.

Rowing, nicks, dents, small marks, a layer of scale and traces of stripping are allowed when

provided that they do not bring the wall thickness and pipe diameter beyond the maximum deviations. Displacement of edges up to 10% of the nominal wall thickness is allowed.

The surface of pipes thermally treated in a protective atmosphere must be free of scale. The presence of an oxide film is allowed.

Repair by welding the base metal of pipes is not allowed.

In the case of repairs by welding pipes that have undergone heat treatment, they are subjected to repeated heat treatment (respectively, over the entire volume or along the welded joint).

2.7. On pipes with a diameter of 57 mm and more, one transverse seam is allowed.

By agreement between the manufacturer and the consumer, one transverse seam is allowed on pipes with a diameter of less than 57 mm.

2.2-2.7. (Modified edition, Amendment No. 5).

2.8. Outer burrs on pipes must be removed. In the place of deburring, the wall thinning by 0.1 mm above the minus tolerance is allowed.

The height of the internal burr or its traces for pipes with an inner diameter of less than 33 mm is established by agreement between the manufacturer and the consumer.

2.9. The ends of the pipes should be cut at right angles and deburred. Tolerance

Remedy for chamfering. The slant of the cut for pipes with a diameter of up to 219 mm should not exceed 1 mm, and for pipes with a diameter of 219 mm and more - 1.5 mm. By agreement between the manufacturer and the consumer, the pipes are made cut in the mill line.

2.10. At the request of the consumer, at the ends of pipes with a wall thickness of 5 mm or more, a chamfer should be removed at an angle of 25 ° -30 ° to the end of the pipe and an end ring with a width of (1.8 ± 0.8) mm should be left. By agreement between the manufacturer and the consumer, the bevel angle and the width of the end ring can be changed.

2.11. The pipes must withstand the hydraulic test pressure. Depending on the value of the test pressure, pipes are divided into two types:

I - pipes with a diameter of up to 102 mm - test pressure 6.0 MPa (60 kgf / cm 2) and pipes with a diameter of 102 mm and more - test pressure 3.0 MPa (30 kgf / cm 2);

II - pipes of groups A and B, supplied at the request of the consumer with a test hydraulic pressure calculated in accordance with GOST 3845, with an allowable stress equal to 90% of the standard yield strength for pipes of this steel grade, but not exceeding 20 MPa (200 kgf / cm 2).

2.12. Heat-treated pipes made of steels of grades StZsp, StZps (categories 3-5), 10, 15 and 20 with a wall thickness of at least 6 mm must withstand the impact bending test of the base metal. In this case, the norms of impact strength must correspond to those indicated in table. 4.

Table 4

The impact bending test of the base metal of heat-treated pipes made of steel grade 22GYu is carried out at the request of the consumer, the impact strength standards are established by agreement of the parties.

2.13. Heat-treated pipes with a diameter of up to 152 mm inclusive, pipes hot-rolled and without heat treatment with a diameter of more than 20 to 152 mm inclusive and a wall thickness of 0.06 Z) H and less, as well as pipes with heat treatment of the welded joint must withstand the flattening test.

Flattening of heat-treated pipes should be carried out up to the distance between flattening planes H, mm, calculated by the formula

(1 + a) ■ s s

where a is the coefficient for pipes made of steel grades 08Yu, 08kp, 8ps, 08, Yukp, St2kp is 0.09, and for pipes from other steel grades it is 0.08; s - nominal wall thickness, mm;

Z) H - nominal outer diameter of the pipe, mm.

Flattening of pipes without heat treatment should be carried out to a distance equal to 2/3 D H. Flattening of pipes with heat treatment of the welded joint should be carried out to a distance equal to 1/2 Z) H.

At the request of the consumer, flattening of heat-treated pipes with a diameter of over 152 to 530 mm should be carried out to a distance equal to 2/3 Z) H.

2.11-2.13. (Modified edition, Amendment No. 5).

2.14. Pipes up to 108 mm in diameter must withstand the expansion test.

Pipes without heat treatment with a diameter of up to 20 mm, as well as a diameter of 20-60 mm with a wall thickness of more than 0.06 Z) H are not tested for expansion.

The increase in the outer diameter of heat-treated pipes during dispensing must comply with the standards specified in table. 5.

Table 5

The increase in the outer diameter of pipes without heat treatment during expansion should be at least 6%.

At the request of the consumer, the increase in the outer diameter when distributing heat-treated pipes with a wall thickness of up to 4 mm made of steel grades Yukp, St2kp should be at least 12%.

(Modified edition, Amendments No. 1, 3, 4).

2.15. At the request of the consumer, pipes must withstand the tests provided for in paragraphs. 2.16-2.18.

2.16. Heat-treated pipes up to and including 530 mm in diameter must withstand the bend test. The bend radius for pipes with a diameter of up to 60 mm must be at least 2.5 A "for the base metal of pipes with a diameter over 60 to 530 mm - according to GOST 3728. By agreement between the manufacturer and the consumer, the bend radius can be reduced.

2.17. Heat treated pipes with a diameter of 30 to 159 mm with a D / s ratio equal to

12.5 or more must withstand the airborne test. The width of the bend to be bent, measured from the inner surface, must be at least 12% of the inner diameter of the pipe and at least

1.5 wall thickness.

The flange angle should be:

90 ° - for pipes made of steel grades 08, 10, 15, St2;

60 ° - for pipes made of steel grades 20, StZ, St4.

2.18. Pipes with a diameter of 50 mm and more, groups A and B, must withstand the tensile test of the welded joint.

The ultimate tensile strength of a welded joint of pipes with a diameter of 219 to 530 mm that have undergone heat treatment throughout the pipe volume or heat treatment of the welded joint must comply with the standards specified in table. 1. The tensile strength of a welded joint of pipes with a diameter of 50 to 203 mm, which have undergone heat treatment throughout the pipe volume or heat treatment of the welded joint, must be at least 0.9 of the norms specified in Table. one.

The tensile strength of a welded joint of pipes without heat treatment with a diameter of 50 mm and more must comply with the standards specified in table. 2 and 3.

(Modified edition, Amendment 1.3).

2.19. The pipes must be tight.

(Modified edition, Amendment No. 3).

3. RULES OF ACCEPTANCE

The number of pipes in a batch should be no more than, pcs:

1000 - with a diameter of up to 30 mm;

600 - with a diameter of St. 30 to 76 mm;

400 - with a diameter of St. 76 to 152 mm;

200 - with a diameter of St. 152 mm.

(Modified edition, Amendment No. 1).

3.2. In case of disagreement in assessing the quality of the chemical composition, at least one pipe from the batch is taken for inspection.

3.3. Each pipe is subject to inspection of the dimensions and quality of the pipe surface. It is allowed to control dimensions and surfaces selectively on each batch with a single-stage

normal level of control in accordance with the requirements of GOST 18242 *. Control plans are established by agreement between the manufacturer and the consumer.

(Modified edition, Amendment No. 3).

** 3.3a. Welded seams of pipes of groups A, B and C must be subjected to 100% non-destructive testing.

When carrying out non-destructive testing along the perimeter of the entire pipe, the hydraulic test of type I pipes is not allowed.

Instead of non-destructive testing of welded seams of pipes of type I, it is allowed to test each pipe with an increased hydraulic pressure calculated in accordance with the requirements of GOST 3845 at an allowable stress equal to 85% of the yield point for pipes with a diameter of 273 mm and more and 75% of the yield point for pipes with a diameter less than 273 mm, but not exceeding 12 MPa (120 kgf / cm 2).

Group D pipes must be subjected to hydraulic pressure testing or non-destructive testing of the welded seam.

(Modified edition, Amendment No. 5, Amendment).

When inspecting the quality of the seam by non-destructive methods, additional control is carried out by hydraulic pressure on 15% of the pipes from the batch.

By agreement between the manufacturer and the consumer, testing of pipes by hydraulic pressure is not carried out.

(Introduced additionally, Amendment No. 3).

3.4. To check the height of the internal burr, 2% of the pipes from the batch are taken.

3.5. For flattening, expansion, beading, bending, impact strength, tendency of the base metal of pipes to mechanical aging, tension of the base metal and the weld, two pipes are taken from the batch.

The yield point of the base metal of the pipes is determined at the request of the consumer.

At the request of the consumer, the determination of the impact strength is not carried out.

Pipes subjected to the flattening test are not subjected to the expansion test.

(Modified edition, Amendment No. 1).

3.6. Upon receipt of unsatisfactory test results for at least one of the indicators for it, repeated tests are carried out on a double number of pipes selected from the same batch.

Retest results apply to the entire batch.

3.7. Places of welding seams of pipes of groups A, B, C must be checked by non-destructive methods, and the repaired pipes must be tested with hydraulic pressure in accordance with the requirements and. 3.3a of this standard.

Places of welding seams of pipes of group D must be tested by non-destructive methods, or pipes after repair must be tested by hydraulic pressure.

(Modified edition, Amendment No. 5).

4. TEST METHODS

4.1. For quality control, one sample is cut from each selected pipe for each type of test, and for testing for impact strength - three samples for each test temperature.

4.2. The chemical composition of steel is determined in accordance with GOST 22536.0 - GOST 22536.6, GOST 12344 - GOST 12354. Samples for determining the chemical composition are taken in accordance with GOST 7565.

4.3. Inspection of the pipe surface is carried out visually. The depth of defects is checked by filing or in another way.

It is allowed to control the surface and size of pipes by non-destructive methods according to technical documentation.

(Modified edition, Amendment No. 1).

4.4. Pipes measure:

length - with a tape measure in accordance with GOST 7502;

outer diameter and ovality - with an adjustable measuring bracket in accordance with GOST 2216 or a caliper in accordance with GOST 166, or a micrometer in accordance with GOST 6507;

* On the territory of the Russian Federation, GOST R 50779.71-99 ** is in force.

inner diameter - with a plug in accordance with GOST 14810 or a caliber in accordance with GOST 2015, or by subtracting two wall thicknesses from the outer diameter;

curvature - with a straight edge in accordance with GOST 8026 and a probe;

wall thickness, wall thickness and height of the internal burr - with a micrometer in accordance with GOST 6507 or a wall gauge in accordance with GOST 11358;

displacement of the edges - with a template according to technical documentation or a micrometer in accordance with GOST 6507, or a vernier depth gauge in accordance with GOST 162;

oblique cut - the parameter is provided by the design of the equipment for processing the ends

the bevel angle of the chamfer - with a goniometer in accordance with GOST 5378. In case of disagreement in assessing the quality, the miter of the cut is checked with a square and a probe;

the end ring at the ends of the pipes - with a ruler in accordance with GOST 427;

the depth of surface defects - with a vertical depth gauge according to GOST 162. Measurement of the outer diameter of the pipe is carried out at a distance of at least 15 mm from the end of the pipe for pipes with the ratio of the outer diameter to the wall thickness Z) H / s H equal to 35 or less; at a distance of at least 2 / s Ai - for pipes with a ratio D u / s u over 35 to 75; at a distance of at least D, - for pipes with a D H / s H ratio over 75.

(Modified edition, Amendments No. 1, 3).

4.5. The impact bending test is carried out on longitudinal specimens of type 3 in accordance with GOST 9454, cut from a section of the pipe located at an angle of about 90 ° to the weld.

Impact strength is determined as the arithmetic mean value based on the test results of three samples. On one of the samples, a decrease in impact strength by 9.8 10 4 J / m 2 (1 kgf m / cm 2) is allowed.

The temperature of the impact bending test of pipes made of steel grades 08, 10, 15 and 20 is chosen by the consumer.

(Modified edition, Amendment No. 1).

4.6. The tendency of the base metal of pipes to mechanical aging is determined in accordance with GOST 7268. It is allowed to straighten samples by static load.

4.7. The tensile test is carried out in accordance with GOST 10006 on a longitudinal (in the form of a strip or a pipe segment) proportional to a short sample.

When tested on specimens of a segmented section, the latter is cut from a section located at an angle of about 90 ° to the weld seam, and is not straightened in the calculated part.

Instead of tensile testing, it is allowed to control the ultimate strength, yield strength and relative elongation of pipes by non-destructive methods.

If disagreements arise, the pipes are tested in accordance with GOST 10006.

(Modified edition, Amendment No. 1).

4.8. Flattening test is carried out according to GOST 8695.

(Modified edition, Amendment No. 3).

4.10. The bend test is carried out in accordance with GOST 3728. Pipes with a diameter of 114 mm are tested on cut longitudinal strips 12 mm wide.

4.11. The flanging test is carried out in accordance with GOST 8693. Burr removal is allowed at the flanging section.

4.12. The determination of the temporary resistance of the welded joint of pipes with a diameter of 50-530 mm is carried out on ring samples according to technical documentation.

4.13. Hydraulic testing of pipes is carried out in accordance with GOST 3845 with holding under pressure of 5 s.

4.14. The control of the welded seam is carried out by non-destructive methods (ultrasonic, eddy current, magnetic or X-ray equivalent method) according to the technical documentation.

5. MARKING, PACKAGING, TRANSPORTATION AND STORAGE

5.1. Marking, packaging, transportation and storage - in accordance with GOST 10692.

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the Ministry of Ferrous Metallurgy of the USSR

2. APPROVED AND INTRODUCED INTO EFFECT by the Resolution of the USSR State Committee for Standards dated 25.12.80 No. 5970

Amendment No. 5 was adopted by the Interstate Council for Standardization, Metrology and Certification (Minutes No. 13 of May 28, 1998)

Registered by the IGU Technical Secretariat No. 3166

State name	Name of the national standardization body
The Republic of Azerbaijan	Azgosstandart
Republic of Armenia	Armgosstandart
Republic of Belarus	State Standard of the Republic of Belarus
The Republic of Kazakhstan	Gosstandart of the Republic of Kazakhstan
Republic of Kyrgyzstan	Kyrgyzstandard
The Republic of Moldova	Moldovastandart
the Russian Federation	Gosstandart of Russia
The Republic of Tajikistan	T adjikgosstandart
Turkmenistan	Glavgosinspektsiya "Turkmenstandartlary"
	State Standard of Ukraine

3. REPLACE GOST 10705-63

4. REFERENCE REGULATORY AND TECHNICAL DOCUMENTS

	Item number		Item number
		GOST 11358-89
		GOST 12344-2003
GOST 380-94 *		GOST 12345-2001
		GOST 12346-78
GOST 1050-88		GOST 12347-77
GOST 2015-84		GOST 12348-78
GOST 2216-84		GOST 12349-83
GOST 3728-78		GOST 12350-78
GOST 3845-75	2.11; 3.3a; 4.13	GOST 12351-2003
GOST 5378-88		GOST 12352-81
GOST 6507-90		GOST 12353-78
GOST 6996-66		GOST 12354-81
GOST 7268-82		GOST 14637-89
GOST 7502-98		GOST 14810-69
GOST 7565-81		GOST 16523-97
GOST 8026-92		GOST 18242-72 *
GOST 8693-80		GOST 22536.0-87
GOST 8694-75		GOST 22536.1-88
GOST 8695-75		GOST 22536.2-87
GOST 9045-93		GOST 22536.3-88
GOST 9454-78		GOST 22536.4-88
GOST 10006-80		GOST 22536.5-87
GOST 10692-80		GOST 22536.6-88
GOST 10704-91

5. The limitation of the validity period was lifted by the Resolution of the State Standard of 12.07.91 No. 1247

6. EDITION (November 2005) with Amendments No. 1, 2, 3, 4, 5, approved in December 1986, December 1987, June 1989, July 1991, April 1999 (IUS 2-87, 3-88, 10-89, 10-91, 7-99); Amendment (NUS 5-2005)

Reprinted (as of March 2008).

See notes of FSUE "STANDARTINFORM" (p. 9).

NOTES FGUP "STANDARTINFORM"

1 Specified in the section "Information data" to GOST 10705-80:

GOST 380-94 was replaced by GOST 380-2005;

GOST 18242-72 was replaced by GOST R ISO 2859-1-2007.

2 An amendment has been published in the information index "National Standards" No. 5-2005

to GOST 10705-80 Electric-welded steel pipes. Specifications [see. Edition (June 2001) with Amendments No. 1, 2, 3, 4, 5 and the collection “Metal pipes and fittings to them. Part 3. Welded pipes. Profile pipes "(Edition 2001)]

Editor R.G. Goverdovskaya Technical editor V.N. Prusakova Proofreader V.I. Barentseva Computer layout I.А. Naleykina

Signed for printing on April 29, 2008. Format 60 x 84 1 / s. Offset paper. Times headset. Offset printing. Uel. print sheet 1.40. Academic and Publishing House 1.10. Circulation 97 copies. Zach. 428.

FSUE "STANDARTINFORM", 123995 Moscow, Granatny per., 4.

Typed in FSUE "STANDARTINFORM" on a PC

Printed at the branch of FSUE STANDARTINFORM - type. "Moscow printer", 105062 Moscow, Lyalin per., 6.

STATE STANDARD OF THE UNION OF SSR

ELECTRIC WELDED STEEL PIPES

TECHNICAL CONDITIONS

GOST 10705-80

Publishing house of standards

Moscow

STATE STANDARD OF THE UNION OF SSR

Date of introduction 01.01.82

This standard applies to steel longitudinal electric-welded pipes with a diameter of 10 to 530 mm from carbon and low-alloy steel, used for pipelines and structures for various purposes.

The standard does not apply to steel pipes used for the manufacture of electric heaters.

1. VARIETY

1.1. Dimensions and maximum deviations of pipes must comply with GOST 10704-91

2. TECHNICAL REQUIREMENTS

2.1. Electric-welded steel pipes are manufactured in accordance with the requirements of this standard and according to technical regulations approved in the prescribed manner.

2.2. Depending on the quality indicators, the pipes are manufactured in the following groups:

B - with standardization of the chemical composition from calm, semi-calm and boiling steel grades St1 St2, St3, St4 according to GOST 380-94 and GOST 14637-89, from calm, semi-calm and boiling steel grades 08, 10, 15 and 20 according to GOST 1050- 88, made of steel grade 08Yu in accordance with GOST 9045

В - with standardization of mechanical properties and chemical composition from calm, semi-calm and boiling steel grades St1, St2, St3, St4 in accordance with GOST 380-94 (category 4 in accordance with GOST 16523-89 and category 2-5 in accordance with GOST 14637-89), from calm, semi-calm and boiling steel grades 08, 10, 15 and 20 in accordance with GOST 1050 -88, from steel grade 08Yu in accordance with GOST 9045-93, from low-alloy steel grade 22GYu with the chemical composition given in (pipes with a diameter of 140 to 426 mm) ;

D - with standardization of the test hydraulic pressure.

(Changed edition, Amendment No. 4, Amendment No. 5).

2.3. Pipes are manufactured thermally treated (over the entire volume of the pipe or along the welded joint), hot-rolled and without heat treatment.

Pipes made of steel grade 22GYu are made heat-treated along the welded joint or throughout the entire volume, pipes made of steel grade St1 - without heat treatment.

(Changed edition, Amendment No. 1, Amendment No. 5).

steel grade	Ultimate tensile strength sv, N / mm2 (kgf / mm2)	Yield point st N / mm2 (kgf / mm2)	Elongation d5,%
steel grade


08, 08ps, 10kp 10, 10ps, 15kp,		196 (20)
St2sp, St2kp, St2ps 1 5, 15ps, 20kp,
St3sp, St3ps, St3kp
St4sp, St4ps, St4kp,

Note. At the request of the consumer, pipes with a wall thickness of 4 mm or more made of steel grades St3sp, 15, 15ps are manufactured with a yield point of 235 N / mm2 (24 kgf / mm2), a relative elongation of 23%; from steel grades St4sp, 20, 20ps - with a yield point of 255 N / mm2 (26 kgf / mm2), a relative elongation of 22%.

(Changed edition, Amendment No. 2, Amendment No. 3, Amendment No. 4 Amendment No. 5).

Steel grade	Temporary resistance rupture sv, N / mm2 (kgf / mm2), with the outer diameter of the pipes D, mm	fluidity st, N / mm2 (kgf / mm2)	with outer diameter of pipes
			from 10 to 60 at wall thickness
			more than 0.06 D	0,06 D and less
	not less

08ps, 08kp, St1ps, St1kp

10kp, St2kp
10ps, St2ps








St4kp, St4ps

Note. At the request of the consumer, for pipes of all steel grades with a diameter of 10 to 60 mm, the relative elongation increases by 3% in comparison with the standards given in table. ...

Steel grade	Wall thickness,	Temporary resistance break sv,	Yield strength st, N / mm2 (kgf / mm2)	Elongation ds,%, with outer diameter of pipes D, mm
				St. 152 to 244.5	St. 244.5 to 377	St. 377 to 530
	not less
08.08ps, 08kp
10, 10ps, 10kp, St2kp
St2sp, St2ps

15, 15ps, 15kp,
20, 20ps, 20kpp
St3sp, St3ps,

St4sp, St4ps,

	All thicknesses

(Changed edition, Amendment No. 1, Amendment No. 3, Amendment No. 4, Amendment No. 5).

2.6. ... Cracks, captivity, sunsets, flaws and risks are not allowed on the pipe surface.

The surface of pipes thermally treated in a protective atmosphere must be free of scale. The presence of an oxide film is allowed.

Repair by welding the base metal of pipes is not allowed.

In the case of repairs by welding pipes that have undergone heat treatment, they are subjected to repeated heat treatment (respectively, over the entire volume or along the welded joint).

(Changed edition, Amendment No. 1, Amendment No. 4, Amendment No. 5).

2.7. For pipes with a diameter of 57 mm and more, one transverse seam is allowed.

By agreement between the manufacturer and the consumer, one transverse seam is allowed on pipes with a diameter of less than 57 mm.

2.8. Outer burrs on pipes must be removed. In the place of deburring, the wall thinning by 0.1 mm above the minus tolerance is allowed.

The height of the internal burr or its traces for pipes with an inner diameter of less than 33 mm is established by agreement between the manufacturer and the consumer.

(Modified edition, Amendments No. 1, 3).

2.10. At the request of the consumer, at the ends of pipes with a wall thickness of 5 mm or more, a chamfer should be removed at an angle of 25-30 ° to the end of the pipe and an end ring with a width of 1.8 mm ± 0.8 mm should be left. By agreement between the manufacturer and the consumer, the bevel angle and the width of the end ring can be changed.

2.11. The pipes must withstand the hydraulic test pressure. Depending on the value of the test pressure, pipes are divided into two types:

I - pipes up to 102 mm in diameter - test pressure 6.0 MPa (60 kgf / cm2) and pipes with a diameter of 102 mm and more - test pressure 3.0 MPa (30 kgf / cm2);

II - pipes of groups A and B, supplied at the request of the consumer with a test hydraulic pressure calculated in accordance with GOST 3845-75, with an allowable stress equal to 90% of the standard yield strength for pipes of this steel grade, but not exceeding 20 MPa (200 kgf / cm2).

(Changed edition, Amendment No. 3, Amendment No. 5).

(Changed edition, Amendment No. 1, Amendment No. 4, Amendment No. 5).

Flattening of heat-treated pipes should be carried out up to the distance between flattening planes H, mm, calculated by the formula

where a- the coefficient for pipes made of steel grades 08Yu, 08kp, 8ps, 08, 10kp, St2kp is 0.09, and for pipes made of other steel grades is 0.08;

S is the nominal wall thickness, mm;

Dн is the nominal outer diameter of the pipe, mm.

At the request of the consumer, flattening of heat-treated pipes with a diameter of over 152 to 530 mm should be carried out to a distance equal to 2/3 Dн.

(Changed edition of Amendment No. 1, Amendment No. 3, Amendment No. 4, Amendment No. 5).

2.14. Pipes up to 108 mm in diameter must withstand the expansion test.

Pipes without heat treatment with a diameter of up to 20 mm, as well as a diameter of 20-60 mm with a wall thickness of more than 0.06 DH are not tested for expansion.

Increased outer diameter of heat treated. pipes during distribution must comply with the standards specified in.

The increase in the outer diameter of pipes without heat treatment during expansion should be at least 6%.

At the request of the consumer, the increase in the outer diameter when distributing heat-treated pipes with a wall thickness of up to 4 mm made of steel grades 10kp, St2kp should be at least 12%.

(Modified edition, Amendments No. 1, 3, 4).

2.15. At the request of the consumer, the pipes must withstand the tests provided for in paragraphs. -

The tensile strength of a welded joint of pipes with a diameter of 219 to 530 mm, which have undergone heat treatment throughout the pipe volume or heat treatment of the welded joint, must comply with the standards specified in Art. The tensile strength of a welded joint of pipes with a diameter of 50 to 203 mm, which have undergone heat treatment for the entire volume of the pipe or heat treatment of the welded joint, must be at least 0.9 of the standards specified in Art.

The tensile strength of a welded joint of pipes without heat treatment with a diameter of 50 mm and more must comply with the standards specified in table. and .

2.19. The pipes must be tight.

(Modified edition, Amendment No. 3).

3. RULES OF ACCEPTANCE

with the addition of the chemical composition of steel in accordance with the document on the quality of the manufacturer of the workpiece.

The number of pipes in a batch should be no more than, pcs:

1000 - with a diameter of up to 30 mm;

600 - with a diameter of St. 30 to 76 mm;

400 - with a diameter of St. 76 to 152 mm;

200 - with a diameter of St. 152 mm.

3.2. In case of disagreement in assessing the quality of the chemical composition, at least one pipe from the batch is taken for inspection.

(Modified edition, Amendment No. 3).

3.3a. Welded seams of pipes of groups A, B and C must be subjected to 100% non-destructive testing.

When carrying out non-destructive testing along the perimeter of the entire pipe, the hydraulic test of type I pipes is not allowed.

Instead of non-destructive testing of welded seams of pipes of type I, it is allowed to test each pipe with an increased hydraulic pressure calculated in accordance with the requirements of GOST 3845-75 at an allowable stress equal to 85% of the yield strength for pipes with a diameter of 273 mm and more and 75% of the yield strength for pipes with a diameter of less than 273 mm, but not exceeding 12 MPa (120 kgf / cm2).

Group D pipes must be subjected to hydraulic pressure testing or non-destructive testing of the welded seam.

(Introduced additionally, Amendment No. 3). (Modified edition, Amendment No. 5). (Amendment,).

3.4. To check the height of the internal burr, 2% of the pipes from the batch are taken.

3.5. For flattening, expansion, beading, bending, impact strength, tendency of the base metal of pipes to mechanical aging, tension of the base metal and the weld, two pipes are taken from the batch.

The yield point of the base metal of the pipes is determined at the request of the consumer.

At the request of the consumer, the determination of the impact strength is not carried out.

Pipes subjected to the flattening test are not subjected to the expansion test.

(Modified edition, Amendment No. 1).

3.6. Upon receipt of unsatisfactory test results for at least one of the indicators for it, repeated tests are carried out on a double number of pipes selected from the same batch.

Retest results apply to the entire batch.

Places of welding seams of pipes of group D must be tested by non-destructive methods, or pipes after repair must be tested by hydraulic pressure.

(Introduced additionally, Amendment No. 1, Amended edition, Amendment No. 5).

4. TEST METHODS

4.1. For quality control, one sample is cut from each selected pipe for each type of test, and for testing for impact strength - three samples for each test temperature.

4.3. Inspection of the pipe surface is carried out visually. The depth of defects is checked by filing or in another way.

It is allowed to control the surface and dimensions of pipes by non-destructive methods according to technical documentation.

(Modified edition, Amendment No. 1).

4.4. Pipes measure:

length - with a tape measure but GOST 7502-89.

outer diameter and ovality - adjustable with a measuring bracket in accordance with GOST 2216-84 or a caliper in accordance with GOST 166-89 or a micrometer in accordance with GOST 6507-89 ;;

inner diameter - with a plug in accordance with GOST 14810-69, or with a caliber in accordance with GOST 2015-84, or by subtracting two wall thicknesses from the outer diameter;

curvature - with a straight edge in accordance with GOST 8026-92 and a probe;

wall thickness, wall thickness and height of the internal burr - with a micrometer in accordance with GOST 6507 -90 or a wall gauge in accordance with GOST 11358-89;

displacement of the edges - with a template according to technical documentation or a micrometer according to GOST 6507-90 or a vernier depth gauge according to GOST 162-90;

the end ring at the ends of the pipes - with a ruler in accordance with GOST 427 -75;

the depth of surface defects - using a barbell depth gauge in accordance with GOST 162-90. The measurement of the outer diameter of the pipe is carried out at a distance of at least 15 mm from the end of the pipe for pipes with the ratio of the outer diameter to the wall thickness D H / S H equal to 35 or less; at a distance of at least 2/3 DH - for pipes with a ratio D H / S H over 35 to 75; at a distance of at least DH - for pipes with ratio D H / S H over 75.

(Modified edition, Amendments No. 1, 3).

4.5. Impact bending test is carried out on longitudinal specimens of type 3 according to GOST 9454-78 cut from a pipe section located at an angle of about 90 ° to the weld.

Impact strength is determined as the arithmetic mean value based on the test results of three samples. On one of the samples, a decrease in impact strength by 9.8 · 104 J / m2 (1 kgf · m / cm2) is allowed.

The temperature of the impact bending test of pipes made of steel grades 08, 10, 15 and 20 is chosen by the consumer.

(Modified edition, Amendment No. 1).

4.6. The tendency of the base metal of pipes to mechanical aging is determined in accordance with GOST 7268-82. Straightening of samples by static load is allowed.