Tecnologia em Metalurgia, Materiais e Mineração (Dec 2012)
Tribology; Cold rolling mill roll; Hard chrome; Surface texturing.
Abstract
The present work analyzes the tribological behavior of surface modifications often used in cold rolling mill rolls. Different surface modifications were carried out on samples produced from a fragment of the rolling mill roll: i) texturing; ii) chromium plating; iii) texturing with subsequent hard chrome plating; iv) and hard chrome plating with subsequent texturing. Before the surface modifications the samples were heat treated and ground on both faces. Wear tests were performed using a reciprocating movement of a ball over flat configuration under a load of 9.8 N. It is observed that there is no significant change in the coefficient of friction as a function of surface modification. Surface texturing increases the wear of the counter body, while the hard chromium coating reduces it. The addition of hard chromium coating promotes the formation of a tribolayer on the counter body consisting of chromium and oxygen. On the other hand, for the samples without hard chrome coating, the tribolayer consists of iron and oxygen
Keywords