Effect of Heating Temperature on Austenite Grain Size of X80 Steel Slab

Effect of heating temperature on austenite grain size of X80 steel slab was investigated using optical microscope in this study. The results present that the microstructures are homogeneous and the grain size increases slowly with the temperature increasing from 1105°C to 1165°C. However, the abnormal growth phenomenon can be observed in the samples heated at 1195-1210°C. The reason is that all second phase particles except TiN dissolves in austenite at 1195-1210°C. The practical heating temperature range of X80 steel slab is 1110-1165°C.