HEAT-RESISTANT STEEL Russian patent published in 2012 - IPC C22C38/32 

FIELD: metallurgy.

SUBSTANCE: steel contains the following, wt %: carbon 0.001- 0.009; silicone 0.005-0.10; manganese 0.2-0.4; chrome 8.5-9.5; cobalt 2.5-4.0; molybdenum 0.4-0.6; tungsten 1.8-3.0; vanadium 0.15-0.30; niobium 0.04-0.09; aluminium not more than 0.015; nickel not more than 0.2; calcium 0.005-0.05; magnesium of 0.005 to 0.05; nitrogen 0.04-0.10; cerium 0.02-0.05; magnesium 0.005-0.05; boron 0.003-0.01; phosphorus not more than 0.015; sulphur not more than 0.010; lead, stannum, arsenic not more than 0.006 each; iron is the rest; at ratio of nitrogen concentration to carbon concentration: ratio of total content of nitrogen and carbon to total content of vanadium and niobium: and total content of tungsten and molybdenum of not less than 2.3 and not more than 3.2. Steel has fine-grain structure with grain size of 10-40 nm after plastic deformation and heat treatment at normalisation temperature of 1040-1060°C and drawing temperature of 740-780°C.

EFFECT: steel is characterised with high level of heat resistance, ductility, impact strength and stability at long-term isothermic exposures.

2 cl, 2 tbl