Title: Fracture failure analysis of 4Cr13 stainless steel linkages in circuit breakers
Highlights:
Failure analysis of 4Cr13 stainless steel components was studied. (2) Effect of heat treatment on mechanical properties of components was investigated. (3) Fracture failure mode was quasi-cleavage fracture under overloading condition
Fracture failure analysis of 4Cr13 stainless steel linkages in circuit breakers
WU Wang-ping1,*
1School of Mechanical Engineering, Changzhou University, Changzhou Jiangsu 213164
Abstract
In this study, the fracture failure of the 4Cr13 stainless steel linkage components in circuit breakers was
studied. The microstructure and morphology of fracture surface were observed by scanning electron microscopy
and optical microscopy. A micro-Vickers tester measured the hardness of the components. The tensile strength
and strain of the components were determined by a universal testing machine. The results show that fracture
failure mode was quasi-cleavage fracture, and some dimples and edges of cleavage were present on the fracture
surface. The substandard sample exhibited higher hardness than the standard sample. The high hardness could
cause the strong rigidity and less toughness, which was not helpful to bend the samples to form hook structure.
The heat treatment influenced the mechanical properties of the 4Cr13 components. With increasing the
tempering temperature, the hardness of the component was decreased when the quenching temperature was kept
stable.
Keywords: Cleavage fracture; Defects; Failure modes; Fracture surfaces