Study on Microstructure Evolution Rule of GH4700 Ni-base Alloy Tube During Cold Rolling and Intermediate Annealing Treatment

The microstructure evolution rule of GH4700 alloy during cold rolling and intermediate annealing was studied by optical microscope,and the dynamic equation of recrystallization grain growth during intermediate annealing was established.The research results show that with the increase of cold rolling deformation variable,defor-mation uniformity of the microstructure grains gradually change better,the yield and tensile strength increase and the elongation of GH4700 alloy decreases;the microstructure can achieve full recrystallization and distribute uniformly at the annealing temperature of 1130 ℃ and holding time of 15 min;the grain size predicted by the proposed grain growth model coincides with the experimental results well.