SEAMLESS HIGH-STRENGTH PIPE OF OIL SORTAMENT IN HYDROGEN SULFIDE-RESISTANT PERFORMANCE Russian patent published in 2017 - IPC C22C38/24 F16L9/02 

FIELD: metallurgy.

SUBSTANCE: invention relates to a hydrogen sulfide-resistant steel composition used for the manufacture of seamless tubing and casing pipes intended for operation in vertical, horizontal and directional wells located in moderate macroclimate regions, the environment of which contains hydrogen sulphide at a partial pressure of more than 1.5 MPa (15.0 kgf/cm²). Pipes are made of steel containing components in the following ratio, wt %: carbon 0.24-0.30, silicone 0.15-0.45, manganese 0.50-0.95, chrome 0.80-1.30, molybdenum 0.50-1.00, nickel not more than 0.30, copper not more than 0.30, aluminium 0.02-0.05, sulphur not more than 0.007, phosphorus not more than 0.015, nitrogen not more than 0.010, vanadium 0.03-0.08, the rest - iron and unavoidable impurities, including arsenic not more than 0.010, lead not more than 0.020, tin not more than 0.020, bismuth no more than 0.001, antimony not more than 0.005 and zinc not more than 0.005. Contamination of steel with non-metallic inclusions does not exceed the average score of 1.5 for oxides and silicates of each type and 1.0 for sulphides.

EFFECT: resistance to sulfide corrosion cracking under tension increases while achieving a high level of pipe strength properties.

2 cl, 3 tbl, 1 ex