Fracture Analysis of GCr15 Steel Ball Screw Nut

Abstract

This paper dealt with the fracture failure of a GCr15 steel ball screw nut. Through testing and analysis of hardness, microstructure, scanning electron microscopy and energy dispersive spectrum meter, it was found that there are local carbide network, few oversized carbide particles and metallic inclusions. The analysis showed that carbide network was failed to be eliminated through spheroidizing annealing treatment, while the presence of non-uniform carbide particles and metallic inclusions easily induced the crack and consequently led to the fracture of the nut.