STAINLESS STEEL FOR OIL WELLS AND PIPE MADE OF STAINLESS STEEL FOR OIL WELLS Russian patent published in 2016 - IPC C22C38/52 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, specifically to stainless steel used for manufacturing pipes for oil wells. Said steel contains following substances, in wt%: C not more than 0.05, Si not more than 1.0, Mn from 0.01 to 1.0, P not more than 0.05, Si less than 0.002, Cr from 16 to 18, Mo from 1.8 to 3, Cu from 1.0 to 3.5, Ni from 3.0 to 5.5, Co from 0.01 to 1.0, Al from 0.001 to 0.1, O not more than 0.05 and N not more than 0.05, rest is Fe and unavoidable impurities. Content of components in steel satisfy expressions: Cr+4Ni+3Mo+2Cu≥44 and Cr+3Ni+4Mo+2Cu/3≤46.

EFFECT: steel has high resistance to high-temperature corrosion and yield strength is not less than 862 MPa.

15 cl, 2 tbl