TUBE FROM HIGH-STRENGTH STAINLESS STEEL WITH HIGH CRACKING RESISTANCE AT STRAINS IN SULPHIDE-BEARING MEDIUM AND HIGH-TEMPERATURE GAS CORROSION RESISTANCE ON EXPOSURE TO CARBON DIOXIDE Russian patent published in 2012 - IPC C22C38/44 

FIELD: metallurgy.

SUBSTANCE: proposed steel contains the following substances, in wt %: C:0.05% or less, Si: 1.0% or less, P: 0.05% or less, S: less than 0.002%, Cr: not over 16% to 18% or less, Mo: not over 2% to 3% or less, Cu: 1% to 3,5%, Ni: 3% or more and less than 5%, Al: 0.001% to 0.1% and O: 0.01% or less, Mn: 1% or less and N: 0.05% or less, Fe and impurities making the rest. Content of Mn and N satifies the following conditions: [Mn] × ([N] - 0.0045) ≤ 0.001. Steel microstructure comprises, mainly, martensite phase and ferrite phase in amount of 10 to 40 vol. % and 10 vol. % or less of residual austenite phase.

EFFECT: higher cracking and corrosion resistance.

3 cl, 1 dwg, 2 tbl, 1 ex