Decarburization Effects on Fatigue Behavior of Leaf Spring Material

Abstract

Decarburization occurs on heat treated components. At leaf spring manufacturers, the occurrence of decarburization, which has a negative impact on fatigue, starts at hot rolled leaf spring steel raw materials' production process. The decarburization rate of the raw material, which is taken through a heat treatment, increases during the leaf spring manufacturing process. Through metallographic analyses and experimental tests, this study manifests how leaf spring's resistance to fatigue is affected by the correlation of ferrite structure occurred by decarburization on heat treated leaf springs, the surface hardness, and the permanent surface tension to be occurred during the shot peening process. This study conveys the techniques that can be applied to obtain low decarburization in leaf spring manufacturing, and the improvements achieved through optimization of high temperature treatment times of materials through use of thermographic survey at heat treatment furnaces. Copyright © 2013 SAE International.