OIL SCHEDULE COLD-RESISTANT PIPE Russian patent published in 2015 - IPC C22C38/04 C22C38/06 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, namely to structural cold-resistant steels used to manufacture oil schedule pipes, in particular for oil and gas production, that can be operated both under general conditions, and under macroclimatic cold at temperature decreased to minus 60°C. The pipe is made from hardened and tempered steel containing carbon, silicon, manganese, aluminium, sulphur, phosphorus, chrome, nickel, copper, nitrogen, iron and inevitable admixtures at the following ratio, wt %: C 0.28-0.34, Si 0.15-0.37, Mn 0.90-1.20, Al 0.02-0.05, S max. 0.010, P max. 0.015, Cr max. 0.25, Ni max. 0.25, Cu max. 0.25, N max. 0.012, Fe and inevitable admixtures, including V, Mo and Ti - rest.

EFFECT: pipe has ultimate strength 900 MPa or below, yield strength 830 MPa or below, impact strength at 0°C at least 41 J and impact toughness at -60°C at least 70 J/cm².

2 dwg, 3 tbl