HIGH-STRENGTH AND HIGH-TOUGH NONMAGNETIC WELDABLE STEEL Russian patent published in 2007 - IPC C22C38/58 C21D1/18 C21D8/00 

FIELD: ferrous metallurgy.

SUBSTANCE: invention proposes high-strength, high-tough, nonmagnetic weldable steel comprising the following components, wt.-%: carbon, 0.04-0.09; silicon, 0.1-0.6; chrome, 21.0-23.0; manganese, 14.0-16.0; nickel, 7.0-9.0; molybdenum, 1.0-2.0; nitrogen, 0.45-0.55; vanadium, 0.1-0.3; cerium, 0.001-0.0030; calcium, 0.005-0.010; boron, 0.001-0.010, and iron and imminent impurities, the balance. The following conditions must be accomplished: [Ni] + 0.1 x [Mn] - 0.01 x [Mn]² + 18 [N] + 30 [C] = 17-22 and [Cr] + 1.5 [Mo] + 0.48 [Si] + 2.3 [V] = 23-27, [C]/[N] = 0.09-0.15 wherein [Ni], [Mn], [N], [C], [Cr], [Mo], [V] and [Si] mean concentrations of nickel, manganese, nitrogen, carbon, chrome, molybdenum, vanadium and silicon in steel, respectively. Nonmagnetic steel possesses high strength, tenacity with enhanced stability of austenite at 600-700°C and can be used in machine engineering, ship building, drilling industry and medicinal technique.

EFFECT: improved and valuable properties of steel.

2 cl, 2 tbl