REFRACTORY MARTENSITIC STEEL Russian patent published in 2015 - IPC C22C38/54 

FIELD: metallurgy.

SUBSTANCE: steel contains in wt %: carbon - 0.08-0.12, silicon not over 0.13, manganese 0.4-0.6, chromium 9.0-9.5, nickel from over 0.1 to 0.3, tungsten 1.2-1.7, molybdenum 0.5-0.8, vanadium 0.18-0.25, niobium 0.04-0.07, nitrogen not over 0.005, boron 0.01-0.014, cobalt from over 3.0 to 3.5, sulphur not over 0.006, phosphorus not over 0.01, aluminium not over 0.01, copper not over 0.03, titanium minimum 0.01, iron - the rest.

EFFECT: steel has increased creep resistance.

4 tbl, 1 ex