The Thermal Fatigue Behavior of Ni-based Alloying Infiltrated Layer on Cast Steel Substrate

The Ni-based infiltrated layer was fabricated through vacuum infiltration casting technology on ZGCr5Mo substrate. The thickness of infiltrated layer was 0. 6-1. 2mm. The thermal cycling behavior was investigated. The surface appearance and composition of Ni-based infiltrated layer was studied by means of SEM and XRD. The results show that the oxidation happened only when the thermal cycling times was less than 20. The micro-crack appeared on the surface of infiltrated layer when thermal cycling times was more than 90. The micro-crack ran through the whole infiltrated layer to substrate. There were micro-cracks parallel to the surface of infiltrated layer and emanative micro-cracks at the interface between the infiltrated layer and substrate. The thermal cycling times was deceased with the increasing thickness of infiltrated layer. The main composition was oxides of Ni and Cr, complicated oxide of Ni/Cr.