STEEL WITH STRUCTURE OF LOW-CARBON MARTENSITE Russian patent published in 2012 - IPC C22C38/58 

FIELD: metallurgy.

SUBSTANCE: steel contains, in wt %: carbon 0.182 - 0.272, chromium 1.2 - 4.0, nickel 0.3 - 4.0, manganese 1.0 - 3.0, molybdenum no more than 3.0, vanadium no more than 0.3, copper no more than 2.5, titanium no more than 0.1, niobium no more than 0.15, silicium no more than 0.6, nitrogen 0.001 - 0.25, calcium no more than 0.15, cerium no more than 0.15, rare-earth metals no more than 0.03, iron - the rest. After thermohardening with a strain heating or after austenitising with cooling at smooth air and after subsequent release it has a rack and globular martensitic structure.

EFFECT: steel has increased impact hardness and strength, high hardenability and processability in the manufacture of welded structures and metallurgical semi-finished products.

2 dwg, 4 tbl