ELECTRIC WELDED STEEL PIPES
Specifications
GOST 10705-80
Date Introduction 01.01.82
This standard applies to steel longitudinal electric-welded pipes with a diameter of 10 to 530 mm made of 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 thermal electric heaters.
(Modified edition, Rev. No. 5).
1. VARIETY
1.1. The 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, pipes are made of the following groups:
А - 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 1 in accordance with GOST 14637-89);
B - with standardization of the chemical composition from 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 9045-93, from low-alloy steel grade 22GYu with the chemical composition given in table. 1a (pipes with a diameter of 140 to 426 mm);
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 according to GOST 1050-88, from steel grade 08Yu according to GOST 9045-93, 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.
(Modified edition, Rev. No. 5).
2.3. Pipes are made thermally treated (throughout the pipe volume or along a welded joint), hot-rolled and without heat treatment.
The type of heat treatment for the entire pipe volume is selected 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.
Table 1a
(Modified edition, Rev. No. 5).
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
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 strength of 235 N /mm 2 (24 kgf /mm 2 ) , relative elongation 23%; made of steel grades St4sp, 20, 20ps - with a yield point of 255 N /mm 2 (26 kgf /mm 2 ), relative elongation 22%.
(Modified edition, Amendment No. 5).
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 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 table. 3.
Table 2
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.
Table3
(Modified edition, Rev. No. 5).
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 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 table. 3.
(Modified edition, Rev. No. 5).
2.6. ... Cracks, captivity, sunsets, flaws and risks are not allowed on the pipe surface.
Ragging, nicks, dents, small marks, a layer of scale and traces of stripping are allowed provided that they do not deduce the wall thickness and pipe diameter beyond the
