Precision cold forging of e.g. tracked packing disc for ball races - now applied to blanks obtd. by hot forging inverse extrusion and cutting etc.

摘要

Cold forging metal working process is used in fabrication of precisely dimensioned pieces, e.g. packing discs with a ball bearing track on each major face, being applied to blank of final required mass and relieved of all internal stresses. Blank can be obtd. by hot forging and shot-blasting, by inverse extrusion, by cutting away material, or by inverse extrusion and punching followed by global tempering and phosphation. Process may comprise an ionic nitration treatment which replaces traditional thermal treatments, and pieces with high resistance to friction may be of low alloy steels of the type XC 38 or 45M5. Pieces with high wear resistance and high compressive strengths may be of steel alloys of the 30CD4 or the 30 CD 12 type.