CORROSION-PROOF HIGH-STRENGTH STEEL USED IN CRYOGENIC TECHNIQUE Russian patent published in 2006 - IPC C22C38/52 

FIELD: development of corrosion-proof high-strength steels for cryogenic machine engineering, namely for making highly loaded welded parts.

SUBSTANCE: steel for cryogenic technique operating at temperature up to 20 K contains components at next relation, %: carbon, up to 0.05; chrome, 11.2 - 12.5; nickel, 7.0 - 8.0; cobalt, 5.6 - 7.0; molybdenum, 3.7 - 4.5; niobium, up to 0.5; cerium, up to 0.1; cadmium, up to 0.05; barium, up to 0.02; iron, the balance. After melting of such steel relation of its structural components, namely of austenite to martensite is to be 1 : 1. Invention provides enhanced ductility and impact viscosity of steel at 20 K. Steel according to invention has σ_B = 1350 - 1500 MPa at 20°C, percentage elongation δ = 14 - 20 % and impact viscosity KCV = 30 -50 J/cm².

EFFECT: high strength, improved ductility and impact viscosity of steel.

2 tbl