Machine part and method for manufacturing same

Abstract

A mechanical component 1 composed of a steel is surface-hardened by nitriding, and specifically has a surficial layer 2 raised in the surface hardness by the nitriding, and an inner portion 3 not affected by the nitriding and showing a nearly constant hardness. Vickers hardness of the inner portion 3 is adjusted to 190 to 260 HV, Vickers hardness of the surficial portion 2 measured at a reference position corresponded to a 50 μm depth from the component surface is adjusted to 340 to 460 HV, and effective depth of hardened layer measured from the component surface 4, where a Vickers hardness of 270 HV is achieved, is adjusted to 0.3 mm or more. This makes it possible to provide a mechanical component which is composed of a steel and surface-hardened by nitriding, and is successfully improved in the strength and bending straightening property, and also to provide a method of fabricating the same.

Dependencies are inferred from the claim text.