CASTING STEEL Russian patent published in 2003 - IPC

FIELD: metallurgy of casting steels used in shipbuilding for manufacture of massive units working under action of static and dynamic loads. SUBSTANCE: steel possesses enhanced toughness, ductility and cracking resistance in solidifying and resistance to brittle failure. Casting steel contains the following components, mass-%: carbon, 0.17-0.22; silicon, 0.17-0.37; manganese, 0.40-0.70; nickel, 3.20-4.50; copper, 0.70-1.00; molybdenum, 0.38-0.50, chromium, 0.3-0.4, the remainder being iron. Content of sulfur and phosphorus shall not exceed 0.025% each or 0.04% in sum. Said steel after heat treatment has the following characteristics: yield point, no less than 610 MPa; ultimate strength, 700 MPa; relative elongation, 20% ; relative reduction, 50%; impact work at temperature of 0 C is 100 J. EFFECT: enhanced ductility, toughness and cracking resistance. 1 tbl