METHOD FOR RAISING WORKING LIMIT OF HIGH CARBON STEEL DURING FORGING BY COMBINATION OF SURFACE PLASTIC WORKING WITH HEAT TREATMENT

摘要

PURPOSE:To raise considerably the working limit of high carbon steel during compressive working such as upsetting or heading by deforming the steel to such a degree that the formation of a plastically deformed region is restricted to only a part close to the surface and by carrying out proper heat treatment. CONSTITUTION:High carbon steel is subjected to local plastic working to such a degree that the formation of a plastically deformed region is restricted to only a part close to the surface, and the steel is coated so that the damage of the surface by oxidation or decarburization is prevented to the utmost. The coated steel is heat treated at a proper temp. in an oxidizing atmosphere. The steel may be heat treated in an inert gaseous atmosphere or vacuum without carrying out coating. The surface layer of the high carbon steel is made preponderantly tough and hard.