Rods, pipes, shaped pieces etc. - have surface depressions applied, esp. by ball blasting which are filled with lubricant prior to cold-drawing

摘要

Depressions are made on the surface of rods, pipes and shaped pieces, partic. drive shaft gear tooth profiles, which are filled with lubricant prior to cold-drawing (using a drawing die). The depressions are formed by non-cutting mechanical deformation and are completely separate from each other. A liquid lubricant is preferred, esp. a drawing oil composed of 15% MoS2. Depressions in the shape of spherical segments are produced by ball blasting. Alternative methods used are rolling or rotary hammering, with the mean distance between the depressions produced (i.e. middle to middle) being equal to the mean dia. of the depressions, both of these distances being approx. 0.15 mm. USE/ADVANTAGE - The material surface shows improved lubricant uptake without the use of a phosphatising step before cold-drawin