采用热模拟压缩试验研究铸态TiNiNb合金在变形温度为700~1050℃、应变速率为0.01~10 s-1条件下的热变形特征,基于试验结果建立了铸态TiNiNb合金的热变形本构方程。根据动态材料模型,计算并分析合金的热加工图。利用热加工图确定热变形的流变失稳区,并且获得了试验参数范围内热变形过程的最佳工艺参数,加热温度为750~880℃、应变速率为0.3~10 s-1,或者加热温度为880~950℃、应变速率为0.01~0.5 s-1。 The thermal deformation characteristics of as-cast TiNiNb alloy under the condition of deformation temperature 700 ~ 1050 ℃ and strain rate 0.01 ~ 10 s-1 were studied by thermal simulation compression test. The thermal deformation constitutive equation of as-cast TiNiNb alloy was established based on the experimental results . According to the dynamic material model, calculate and analyze the hot working diagram of the alloy. The hot deformation curves were determined by the hot working drawing. The optimum parameters of the hot deformation process were obtained with the heating temperature of 750 ~ 880 ℃, the strain rate of 0.3 ~ 10 s-1, or the heating temperature Is 880 ~ 950 ℃ and the strain rate is 0.01 ~ 0.5 s-1.