HEAT TREATMENT FOR STRENGTHENING SURFACE OF METALLIC FORMED PRODUCT

摘要

PROBLEM TO BE SOLVED: To easily execute the strengthening of the surface of a metallic formed product with jetting shots. SOLUTION: The shots having 20-200μm size and the same or higher hardness as the formed product hardness are jetted at >=50 m/sec jetting speed by using low temp. compressed gas. The temp. near the surface is raised to A3 transformation point or higher to a ferrous metallic formed product and to recrystallizing temp. or higher to non-ferrous metallic formed product, and also, instantially cooled to room temp. or with the low temp. compressed gas. The low temp. compressed gas is desirable to be <=0 deg.C.