INSTRUMENTAL STEEL Russian patent published in 1998 - IPC

FIELD: metallurgy, namely, production of instrumental steel. SUBSTANCE: instrumental steel comprises, mas.%: carbon, 0.7-1.4; silicium, 0.1-1.2; manganese, 0.1-1.0; tungsten, 0.1-2.5; molybdenum, 3.5-7.5; chromium, 1.5-4.5; vanadium, 0.9-3.0; rare-earth metals, 0.001-0.3; calcium, 0.001-0.25; nitrogen, 0.003-0.2; titanium, 0.01-0.8; aluminium, 0.02-2.0; boron, 0.05-0.2; ferrum, the balance. EFFECT: increased secondary hardness and heat resistance after heat treatment at prolonged cooling. 2 tbl