STAINLESS HIGH-STRENGTH STEEL Russian patent published in 2009 - IPC C22C38/54 

FIELD: metallurgy.

SUBSTANCE: invention concerns metallurgy field and can be used at manufacturing of products from stainless high-strength steel of martensite - austenite class long-exposure at intensive dynamic loads in corrosion-active aqueous medium with presence of solved hydrogen sulfide, chlorine ions, salt of alkaline-earth metals, oil products. Steel contains carbon, chrome, nickel, copper, titanium, aluminium, molybdenum, niobium, cobalt, nitrogen, calcium, boron, cerium, silicon, manganese, sulfur, phosphor, iron and accompanying admixtures, at following ratio of components, wt %: carbon ≤ 0.03, chrome from 8.0 till less than 15.0, nickel 4.0 - 12.0, copper 0.3 - 5.0, titanium 0.01 - 1.0, aluminium 0.01 - 0.6, molybdenum 0.05 - 3.0, niobium 0.05 - 0.4, cobalt 0.01 - 3.0, nitrogen 0.005 - 0.15, calcium ≤ 0.02, boron ≤ 0.005, cerium ≤ 0.02, silicon ≤ 0.8, manganese ≤ 0.8, sulfur ≤ 0.03, phosphor ≤ 0.03, iron and accompanying admixtures are the rest. Nickel and chromic equivalents are associated by following ratio: Cr_equiv / Ni_equiv (1.7 and Ni_equiv - (22.3 ± 3)-0.83Cr_equiv.

EFFECT: providing of high values of yield strength and impact elasticity, and also increased corrosive attack strength under tension.

5 cl, 3 tbl, 1 ex