CASE-HARDENED STEEL ELEMENT AND METHOD OF ITS PRODUCTION Russian patent published in 2014 - IPC C22C38/02 C21D9/32 C23C8/64 

FIELD: metallurgy.

SUBSTANCE: invention relates to case-hardened steel element, to method of its production and case-hardening steel. Steel-hardened steel element is produced at special stages of case-hardening, cooling and quenching. Steel element contains the following components in wt %: C: 0.1-0.40; Si: 0.35-3.0; Mn: 0.1-3; P: 0.03 or less; S: 0.15 or less; Al: 0.05 or less; N: 0.03 or less; Cr: less than 0.2 and Mo: 0.1 or less; Fe and unavoidable impurities making the rest. Its surface layer has first ply with carbon concentration of 0.60-0.85 wt % and martensite structure wherein no oxide layer caused by Si presence exists at grains interface. Second ply has carbon concentration of 0.1-0.4 wt % and martensite structure. Third ply has carbon concentration of 0.1-0.4 wt % and has no martensite structure.

EFFECT: higher strength and homogeneous structure.

25 cl, 7 dwg, 2 tbl