To provide a high performance surface treated steel member by establishing the surface treating means of steel member, in which the stable hardening, etc., of a desired surface position can be executed even in the case the treating member is a thin part.
The treating part of the steel member is made to be the melting state in only the surface layer by high density energy beam irradiation, and successively, rapid cooling of this melted part is executed. Further, in this case, a) the melted part on the surface layer is made to be a state constituted with a full melted layer and an unperfectly melted layer adjoining this. b) The surface layer of the treating part is made to be the melted state in a short time within 'austenitic transformation completing time' in the case of holding to the austenizing temp. c) The irradiating energy beam is divided into plural positions and the surface layer of te treating part is simultaneously made to be the melted state. d) Heat capacity (or thickness) of the whole steel member is made four or more times the heat capacity (melting depth) of the to be part to be treated. It is desirable to execute the treating means, such as the above a) to d), etc. By this method, the surface treated steel member provided with the surface layer part, in which a basic material metal is melted and rapidly solidified, is obtd.
TANIGUCHI TAKAO
OBAYASHI KOJI
WATANABE YOSHI
MOMIYAMA NAOHISA
