The 1st shot-ball peening process which does shot-ball peening treatment on the steel

摘要

PROBLEM TO BE SOLVED: To provide a surface treatment method for steel which forms a nitrided layer containing high concentration N and having suppressed hardness and suppressed thickness of a nitrogen compound layer, and which provides steel properties excellent in wear resistance and fatigue properties.;SOLUTION: A nitriding layer 2 having an N concentration of ≥2 mass% and a thickness of ≥10 μm is formed on the surface layer part of steel by performing a shot peening step where the surface of the steel before treatment is subjected to shot peening; a fluorination step where the steel subjected to the shot peening treatment is heated in a fluorine-containing atmosphere to remove an oxide film on the surface and further to form a fluoride film; and a nitridation step where the steel subjected to the fluorination is subjected to nitridation.;COPYRIGHT: (C)2010,JPO&INPIT