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相变超塑性焊接（ＴＳＷ）是一种利用超塑性流动的低应力、大变形的特殊流变规律的新型固相焊接方法。本文在弹粘塑性模型的基础上，建立了相变超塑性焊接过程的力学模型。数值模拟结果表明，对于自由边界的相变超塑性焊接接头，随着膨胀率的增大，边界上的应力将逐渐由压应力向拉应力转化；顶锻压力和循环次数既影响拉应力出现的位置，又影响拉应力数值的大小，这两个参数如何合理配合，成为影响接头质量的关键因素。对Ｑ２３５／Ｑ２３５相变超塑性焊接的工艺试验研究表明，接合面中心一定范围内焊合很好，但边界上易于产生张开小口的缺陷，张口出现的位置是由界面应力决定的。
Phase Change Superplastic Welding (TSW) is a new type of solid phase welding method that utilizes the special rheology of low stress and large deformation of superplastic flow. Based on the visco-plastic model, the mechanical model of the phase-change superplastic welding process is established. The numerical simulation results show that the stress on the boundary will gradually change from compressive stress to tensile stress with the increase of the expansion rate for the phase change superplastic welded joints with free boundary. The upsetting pressure and the number of cycles affect both the occurrence of tensile stress Location, but also affect the size of the value of tensile stress, how the two parameters with a reasonable fit has become a key factor affecting joint quality. The experimental study of the Q235 / Q235 phase transition superplastic welding shows that the welding in the center of the joint surface is well within a certain range, but the defect of opening the small opening is easy to occur on the boundary. The position of the opening is determined by the interface stress.