Fracture Analysis of Case Hardening in Kingpins Parts

Kingpin parts are the critical product for heavy vehicles and generally made of 20MnCr5 steel. A kingpin is a metal cylindrical pin that located underneath front end trailer. The mechanism on trailer locks it to road tractor. in this study have undergone case hardening heat treatment after rough machining operation. During operation assembly line, cracks been shown surface. In study, examined with Scanning Electron Microscopy (SEM) analysis, hardness %C potential analysis order determine causes crack formations. It that, not homogeneously distributed therefore fractures occur. exact outcome fracture could be determined. Under scanning electron microscope, becomes clear crack. There no signs hydrogen embrittlement. With present structure, expected even low dynamic load can lead breakage. As result, investigations suggest exposed incorrect parameters.