GOST 8733-74

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  ГОСТ 8733-74

GOST 8733−74 seamless steel Tubes cold and warm. Technical requirements (Changes No. 1−4)

GOST 8733−74

Group В62

INTERSTATE STANDARD

SEAMLESS STEEL TUBES COLD DEFORMED
AND WARM

Technical requirements

Seamless cold and warm deformed pipes.
Specifications

ISS 23.040.10
OKP 12 4000

Date of introduction 1976−01−01

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the Ministry of ferrous metallurgy of the USSR

DEVELOPERS

G. I. Gulyaev, V. P. Sokurenko, N. And. Petrenko

2. APPROVED AND promulgated by the Decree of the State Committee of standards of the Council of Ministers of the USSR dated 19.11.74 N 2561

3. REPLACE GOST 8733−66

4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

5. Limitation of actions taken by Protocol No. 6−94 of the Interstate Council for standardization, Metrology and certification (ICS 3−96)

6. EDITION with Amendments No. 1, 2, 3, 4, approved in March 1976, February 1980, December 1985, April 1992 (IUS 4−76, 4−80, 4−86, 7−92)


This standard applies to cold and warm seamless pipes of General purpose carbon steel and alloy steel.

(Changed edition, Rev. N 4).

1. TECHNICAL REQUIREMENTS

1.1. Pipe manufactured in accordance with the requirements of this standard for technological regulations approved in the prescribed manner.

The pipe dimensions and limit deviations thereon shall be as specified in GOST and GOST 8734 9567.

(Changed edition, Rev. N 3).

1.2. Depending on the quality parameters of the pipe shall be manufactured of the following groups:

B — with standard chemical composition of steel according to GOST 1050, GOST 14959, GOST 4543, GOST 19281;

In — with standard mechanical properties specified in table.1, and the chemical composition of steel grades according to GOST 1050, GOST 14959, GOST 4543, GOST 19281;

G — with standard mechanical properties that are controlled thermally treated samples, and chemical composition of steel grades according to GOST 1050, GOST 14959, GOST 4543, GOST 19281. Norms of mechanical properties shall conform to the requirements of the relevant standards for steel;

D — without standardization of mechanical properties and chemical composition, but with the standard hydraulic test pressure;

E — after special heat treatment. Steel grade, heat treatment regime and norms of mechanical properties are set by the documentation, duly approved.

Table 1

Note. Mechanical properties of pipes made from steel grades not listed in table.1, and the rules of impact strength and relative contraction for steel of all grades are established by agreement between manufacturer and consumer.


(Changed edition, Rev. N 3, 4).

1.3. Pipes are produced heat-treated. Without heat treatment, pipes are divided, in which the ratio of outer diameter to thickness is 50 or more, and at the request of the consumer. In the manufacture of tubes without heat treatment of the norms of mechanical properties are established by agreement between manufacturer and consumer.

Note. By agreement with the consumer allowed to manufacture pipes with respect to /equal to 50 or more, heat-treated.

1.4. On the surface of the pipe are not allowed cracks, slivers, flaws, shells and sunsets.

Some minor nicks, scale (traces of loose scale) that do not impede the inspection, dents, signs of changes, risks and traces of Stripping defects may be allowed, if they cannot make the pipe sizes for maximum deviations.

1.5. At the request of the consumer, the pipe surface must be cleaned from scale.

1.3−1.5. (Changed edition, Rev. N 3).

1.6. The pipe ends should be square-cut and cleaned of burrs; allowed the formation of chamfer when deburring.

1.7. At the request of the consumer at the ends of the pipes to be welded, with wall thickness of 5 mm or more, shall be removed chamfer with the angle of 35° to 40° to the pipe end. This should be left to the socket ring width of 1−3 mm.

1.8. Pipe of all types, pressure (the working conditions of the pipes are specified in the order), shall withstand a test hydraulic pressure () MPa (kgf/cm), calculated according to the formula given in GOST 3845 where  — allowable stress equal to 40% of the temporary tear resistance for a given grade of steel, in N/mm(kgf/mm).

The ability of pipe to withstand hydraulic pressure is provided by the technology of production of pipes.

(Changed edition, Rev. N 3).

1.8. At customer’s request, tubes shall withstand hydraulic pressure, calculated according to the formula in GOST 3845, but not exceeding 20 MPa (200 kgf/cm).

By agreement with the consumer allowed to test the pipes under pressure of over 20 MPa (200 kgf/cm).

Instead of hydrotesting is permitted to carry out inspection of each pipe non-destructive method that provides compliance with the standards of pipe hydraulic test pressure, () MPa (kgf/cm), according to the formula specified in GOST 3845.

(Added, Rev. N 3).

1.9. At customer’s request, heat-treated tubes of steel grades 10, 20 and 15KHM depending on the purpose and conditions of work must be able to withstand one or several technological tests specified in paras.1.10−1.13.

(Changed edition, Rev. N 3).

1.10. Pipe shall withstand a bend test.

1.11. Test distribution must be able to withstand the pipe diameter of 160 mm and a wall thickness of not more than 8 mm on the mandrel with a taper of 1:10 to increase the outer diameter specified in the table.2.

Table 2

1.12. The flattening test shall withstand pipe with a diameter of 22 mm and over with wall thickness of not more than 10 mm to obtain sludinajumi between surfaces distance () in mm, calculated by the formula

,

where is the nominal wall thickness, mm;

 — nominal outside diameter of pipe, mm.

(Changed edition, Rev. N 3).

1.13. Test turn-up cuffs to withstand pipe outer diameter not less than 25 mm and not more than 160 mm with a wall thickness of:

no more than 10% of external diameter for tubes with external diameter up to 60 mm;

no more than 8% of the outer diameter for pipes with outside diameters over 60 to 108 mm;

no more than 6% of the outer diameter — pipe outside diameter in excess of 108 to 140 mm;

no more than 5% of the outer diameter for pipes with outside diameter of more than 140 to 160 mm.

Width bent sides, measured from the inner surface of the pipe, shall be not less than 12% of the inner diameter of the pipe and not less than 1.5 times the wall thickness.

The angle of the flanging shall be:

90° — for pipes of steel grade 10;

60° — for pipes of steel grades 20 and 15KHM.

1.14. (Deleted, Rev. N 3).

2. ACCEPTANCE RULES

2.1. Pipes take by the parties.

The party should consist of pipes of the same size, one grade of steel and one heat treatment followed by one document on quality in accordance with GOST 10692.

The number of pipes in the lot shall be not more than:

400 PCs — for pipes with a diameter less than 76 mm and wall thickness not exceeding 2.5 mm;

200 pieces for pipes of other sizes.

Allowed to increase lot size up to 600 pieces for pipes with diameter of 76 mm and with a wall thickness not exceeding 2.5 mm and up to 300 pieces for pipes of other sizes.

2.2. At customer’s request, the party shall consist of pipes, one made of steel melting.

2.1, 2.2. (Changed edition, Rev. N 3).

2.3. Inspection and measurement shall be subjected to each tube.

2.4. Chemical composition of steel pipes take the document about the quality of the manufacturer of the workpiece.

2.5. To control the mechanical properties, test bend, the hand, flattening and turn-up cuffs pick up two tubes from the party. To control the chemical composition of the selected one pipe from the party.

2.4, 2.5. (Changed edition, Rev. N 3).

2.6. To test for the hardness test 2% of the pipes (but not less than two pipes) from the party.

2.7. The yield strength and Brinell hardness number of steel pipes, the manufacturer shall define periodically at the request of the consumer.

(Changed edition, Rev. N 3).

2.8. (Deleted, Rev. N 3).

2.9. If unsatisfactory test results of at least one of the indicators it is carried out re-testing at twice the sample from the same batch.

The results of repeated tests apply to the entire party.

(Changed edition, Rev. N 3).

3. TEST METHODS

3.1. From each selected batch of pipe cut one sample.

3.2. Inspection of pipes produced without the use of special devices. The depth of the defects check podpravki or otherwise.

Tube lengths of control tape according to GOST 7502.

The curvature of the pipes is controlled straightedge according to GOST 8026 probe on the other 2−034−225.

Diameter and ovality control micrometer smooth MK-type according to GOST 6507, staples sheet according to GOST 18360, 18365 GOST.

The wall thickness of the pipe is controlled by micrometer type MT according to GOST 6507.

Allowed to control the quality of the surface devices according to normative-technical documentation.

3.3. Chemical analysis of steel tubes in case of disputes is carried out according to GOST 22536.0 to GOST 22536.6, GOST 12344−12365 GOST, GOST 28473.

Samples for determining the chemical composition of the steel pipes are selected according to GOST 7565.

3.2, 3.3. (Changed edition, Rev. N 3, 4).

3.4. The tensile test is carried out according to GOST 10006 on the longitudinal proportionate short sample. For samples in the form of a strip or segment of pipe test speed up to yield strength should be not more than 10 mm/min, yield point is not more than 40 mm/min.

Allowed to control the mechanical properties of pipes non-destructive methods according to normative-technical documentation.

In case of disagreement in the evaluation of test results carried out according to GOST 10006.

(Changed edition, Rev. N 2, 3, 4).

3.5. The hardness test is carried out according to GOST 9012 on both ends of the pipe.

On the pipes, subjected to heat treatment in continuous furnaces, hardness tests carried out on one end of the pipe.

Allowed the hardness test carried out on specimens intended for the tensile test.

Allowed to produce a hardness control by nondestructive methods according to normative-technical documentation. In case of disagreement in the evaluation of test results carried out according to GOST 9012.

(Changed edition, Rev. N 3).

3.6. Hydraulic testing of the pipes is carried out according to GOST 3845 with time under pressure of not less than 10 s.

3.7. Test pipe at the bend is carried out according to GOST 3728.

3.8. Test pipes for the distribution is carried out according to GOST 8694.

3.9. Test pipes for flattening is carried out according to GOST 8695.

When discovering a tapered samples tiny tears or other minor defects allowed to re-test flattening of another sample taken from the same tube with the preliminary removal of the surface layer of the sample (inner and outer) to a depth of not more than 0.2 mm.

(Changed edition, Rev. N 3).

3.10. Test pipes on a turn-up cuffs is carried out according to GOST 8693.

4. MARKING, PACKAGING, TRANSPORTATION AND STORAGE

4.1. Marking, packaging, transportation and storage are produced according to GOST 10692.