The superplastic tensile tests of GH4169 alloy at different deformation processes were carried out to investigate the effects of deformation and heat treatment processes on the superplastic behavior of the material.The as-forged GH4169 alloy was annealed at 890℃×10 h+950℃×1 hand at 890℃×10 h+950℃×3 h.The observation of microstructure shows that the grain can be refined effectively by prolonging the second annealing time.The maximummvalue method was used for the superplastic tensile tests at different temperatures.The results show that the elongation of the alloy sample is desirable at 950℃.The elongation of the sample can be increased by prolonging the second annealing time.The strain induced superplasticity method based on the maximum m value method was used for the superplastic tensile test of the alloy.It can be seen that the elongation is the best after 20 min of pre-deformation and stretching time.And the forged GH4169 alloy has an elongation of566% under heat treatment at 890℃×10 h+950 ℃×3 h

which is significantly higher than that of the simple m-value method.