Effects of lubrication and die radius on the friction behavior of Pb-coated sheet steels

Using a strip tensile friction simulator, the influence of lubricant proper ties (viscosity and extreme pressure) and pin radius on the interfacial fri ction and the surface quality of Pb-coated sheet steels is investigated. Ni ne distinct testing conditions are examined by varying the lubricants (thre e oils and two greases) and pin radii (10 and 20 mm). Friction coefficient curves are generated as a function of sliding distance for each condition e xamined and the surface quality of the sheets are evaluated from surface ro ughness and micrographs taken before and after testing. From the experiment al results, tendencies for the interfacial friction and surface finish of P b-coated sheet steels are established with respect to lubricant properties and pin radius. Specifically, the results indicated that the friction coeff icient increases with both the viscosity and extreme pressure (oils only) o f the lubricants. In addition, it was determined that the lubricant propert ies had little influence on the final surface roughness of the deformed she et. Considering the influence of pin size, the results showed that the fric tion coefficient increased with decreasing pin radius values. (C) 2000 Else vier Science S.A. All rights reserved.