A multi-step lubricant evaluation strategy for wire drawing-extrusion-coldheading sequence

The upsetting-sliding, test was used to simulate the characteristic contact conditions of a cold heading sequence comprising two operations, wire draw ing and direct extrusion. Friction conditions for each elementary forging o peration were analysed according to the lubrication parameters, such as age ing of the soaping phosphate line, immersion time in the phosphating bath, and additional lubricants (drawing powder and cold heading oil). The result s enabled: (i) better knowledge and control of the changing friction condit ions as the forging procedures progress; (ii) predicting and remedying lubr ication damage, and (iii) anticipating the geometric variations of the forg ed product according to the friction conditions. (C) 2001 Elsevier Science B.V. All rights reserved.