METHOD AND APPARATUS FOR FORMING LUBRICATING FILM

摘要

A method for forming a lubricating film, which comprises cleaning the surface of pieces of a material for cold plastic working by at least one method selected from the group of shot blasting, sand blasting, alkali degreasing and acid washing, contacting a plurality of the resulting pieces with a lubricant-containing aqueous treating fluid which comprises (A) a water-soluble inorganic salt and (B) one or more or a wax and molybdenum disulfide at 30 to 70ringC for 0.5 to 10 min, taking the pieces out of the treating fluid and subjecting the pieces to the draining of the fluid for 5 to 60 sec, and then applying a hot air having a temperature of 50 to 150ringC to the pieces for 0.5 to 10 min while moving the plurality of them at the same time, to dry the pieces, thereby forming a lubricating film on the surface of the pieces in a deposited amount of 1 to 20 g/m2.