ROUND GAGED PROFILED TOLLED BARS Russian patent published in 2013 - IPC C22C38/18 C21D8/06 

FIELD: metallurgy.

SUBSTANCE: rolled bars are made of steel containing in wt %: carbon - 0.48-0.53, manganese - 0.50-0.75, silicon - 0.36-0.60, sulfur - 0.005-0.020, phosphorus - 0.001-0.030, chromium - 2.70 - 3.20, iron and unavoidable impurities making the rest. Steel contains following substances as impurities, in wt %: molybdenum - not over 0.15, vanadium - not over 0.05, nickel - not over - 0.25, copper - not over 0.25. Rolled stock features austenite grain size not exceeding 5. Content of non-metallic inclusions does not exceeds on the average 3.5. It features also curvature not exceeding 1.0 mm/m, HB hardness not exceeding 241, decarbonised layer not exceeding 1.0% of bar diameter and homogeneous macrostructure.

EFFECT: better mechanical properties and machinability.

2 tbl, 2 ex