HIGH-STRENGTH CORROSION-RESISTANT STEEL AND ARTICLE MADE FROM SUCH STEEL Russian patent published in 2003 - IPC

FIELD: metallurgy; production of high-strength corrosion-resistant steel of austenitemartensite class hardened with nitrogen for manufacture of heavily-loaded parts of machines working at temperatures from minus 70 to 300 C. SUBSTANCE: proposed steel contains the following components, mass-%: carbon, 0.08-0.12; chromium, 13.5-14.5; nickel, 3.5-4.5; nitrogen, 0.15-0.20; molybdenum, 2-2.5; manganese, 1-1.5; vanadium, 0.03-0.05; niobium, 0.03-0.05; silicon, 0.1-0.3; copper, 0.3-0.8; calcium, 0.01-0.03; barium, 0.01-0.03; the remainder being iron. Ultimate strength of steel is 1800-1850 Mpa, yield point is 1400-1450 Mpa, relative elongation is 16-20% and impact viscosity is 60-80 J/sq cm. Steel possesses high resistance to corrosion cracking and retains its properties in salt fog of 5-% NaCl at35 C and bending stress of 1000 Mpa. EFFECT: improved mechanical properties. 3 cl, 2 tbl