This paper present a failure analysis of box-like link-plate. The failed link-plate is fabricated from 42CrMo steel and the surface of internal hole is demanded to be induction-hardened.
Evidences indicate that the failure of link-plate is due to hydrogen. The possible source for hydrogen was introduced during melting and casting process. A great number of non-metallic inclusions in the link-plate material acted as traps of hydrogen.