Microstructural Study of High Temperature Creep in Q460E Steel Based on the Solidification Method

A tensile creep test has been carried out to study the high temperature creep mechanism of Q460E steel and thus develop a better understanding about how the creep phenomenon affects the performance of a cast slab. Because the heating process in the solidification method is more similar to the actual solidification process of casting a slab, the high temperature tensile creep test was conducted by using the solidification method. Further observation of the microstructure was carried out after the tensile creep test has been carried out. The microstructure of the Q460E steel after the high temperature tensile creep test and water quenching observed with a metallographic microscope revealed mainly martensite and retained austenite. From the observation with a transmission electron microscope (TEM) it could be found that dislocation and its substructure were the root cause which triggered high temperature creep deformation of the Q460E steel. In addition, the formation of a subboundary also provided the impetus to creep deformation