The influence of different heat treatment process on microstructure and mechanical properties of flow forming T-250 Co-free maraging steel was investigated in this paper. The α'→γ transformation temperature of solution treated and flow forming steel was measured by thermal dilamation device and the recrystallization temperature of deforming martensite was examined by optical microscope(OM). Hardness and strength changing regulations under various heat treatment conditions was also studied. The microstructur...