Abstract:The property of thermal ductility and hot cracking sensibility for the forge and rolling plate with 70mm thickness nickel alloy were studied using an optical microscope (OM), scanning electron microscope (SEM), and Gleeble 1500 thermal simulation equipment. The results show that the forge and rolling plate have excellent thermal ductility; the samples taken from surface position have higher thermal ductility than those taken from middle position at the same plate. The rolling plate has higher thermal ductility than the forge plate at the lower temperature during heating process. As rising the temperature, the forge plate has higher thermal ductility than the rolling plate. During the cooling process, the forge plate shows higher thermal ductility than the rolling plate. The rupture sections have more smooth morphology, even some sections exist the melt phenomenon. The forge and rolling nickel alloy 690 have high hot cracking sensitivity. The crack number and length increased with the strain increased.