The hot deformation behavior of as-rolled Ni-40 Ti shape memory alloy was investigated by the Gleeble-3500 thermal simulation machine at deformation temperature in range of 650 ℃ to 850 ℃ and strain rate in range of 0.01s

-1

to 1.00s

-1

.The results show that the flow stress of Ni-40 Ti shape memory alloy is affected greatly by strain rate and deformation temperature

and the flow stress is decreased with the increase of deformation temperature and the decrease of strain rate.The hot deformation constitutive relationship is established based on the Arrhenius equation and multivariate linear regression equation

respectively.The error analysis shows that there exists large error between the value of experiment stress and calculated one by the Arrhenius equation.Therefore

the multivariate linear regression constitutive model is more appropriate for the prediction of flow stress of Ni-40 Ti shape memory alloy

whose average relative error is very small.