Abstract: Austenite grain growth phenomena of Q1030 steel at different heating temperatures were studied.In a certain heating temperature range,parts of austenite grains in Q1030 steel grow abnormally,leading to mixed grain phenomena.The inhibition effect of precipitated phase particles at different locations on grain growth was analyzed.The size and volume fraction of the particles at different heating temperatures were calculated by thermodynamic methods,and then the relationship between the pinning force of the particles and heating temperature was discussed.The result shows that the pinning force of the particles reduces sharply in a certain temperature range,resulting in the abnormal growth of partial austenite grains and producing the mixed grain phenomena.