Heat-treatment of semifinished product-sliding surface of shaping members in plastic metal-working apparatus

摘要

A shaping ferrous metal member used in a metal-working apparatus is heat-treated at about 1,000 DEG C. for several hours in an incompletely burning fuel gas, to provide a burned gas atmosphere composed of 0.5 to 5.0% of CO, 8 to 12% of CO2, 0 to 0.5% of O2. A tough iron oxide layer of high quality is tightly deposited with a uniform thickness by said heat-treatment on the surface of shaping metal member which is abrasively contacted by a sliding semifinished metal product. The advantageous effect of this method is that a consumable shaping metal member has a life 2 to 4 times longer than that of a metal member which is conventionally heat-treated in a completely-burning fuel gas.