STEEL OF INCREASED HARDENABILITY AND TREATABILITY Russian patent published in 2009 - IPC C22C38/60 C22C38/54 

FIELD: metallurgy.

SUBSTANCE: invention relates to ferrous metallurgy, particularly to manufacturing of high-strength case-hardened steel for manufacturing of heavy loaded components in automobile industry, particularly toothed wheels of gearboxes, components of undercarriage of tractors and automobile of heavy payload. Steel is made with usage of metallised pellet and contains components in a following ratio wt %: carbon 0.15-0.25, manganese 0.80-1.10, silicon 0.15-0.40, sulphur 0.020-0.065, chrome 0.45-0.80, nickel 0.45-0.75, molybdenum 0.15-0.30, aluminium 0.02-0.06, nitrogen 0.004-0.015, calcium 0.0005-0.0050, boron ≤0.0008, iron and unavoidable admixtures are the rest. Overall content of manganese, chrome and molybdenum is not less than 1.7, and ratio of aluminium to the nitrogen is not less than 1.8. In the capacity of unavoidable admixtures steel contains phosphorus not more than 0.025 wt % and copper not more than 0.2 wt %.

EFFECT: there are increased hardenability properties of steel, improved treatability and reduced distortion at thermal treatment, that provides guaranteed level of consumer properties of manufactured from steel products.

2 cl, 1 ex