Numerical investigation has been employed to analysis stress distribution in 9Cr/2.25Cr dissimilar welded rotor undergoing welding and heat treatment in order to help optimize structural design. The simulated residual stress on inner and outer cylindrical surface has been validated with experimental data. Distribution and evolution of welding residual stress along weld center line through thickness has also been investigated. It is found that expansion due to martensitic phase transformation in cap weld and shrinkage in nominal HAZ determines the distribution of residual stress on outer cylindrical surface. Meanwhile, expansion caused by martensitic phase transformation and bending effect in annular structure is responsible for the evolution and distribution of through-wall residual stress. Distribution and peak value of through-wall welding residual stress remains after the weld height reaches a certain value (it is about 30% thickness from the inner cylindrical surface in this work), which provides a possibility to predict stress distribution with less time. Meanwhile, post weld heat treatment (PWHT) can release residual stress effectively. Hence, more attention has been paid to as-welded residual stress. Compared with 2.25Cr weld filler, 9Cr weld filler induces greater compressive hoop stress in the newly deposited weld metal and decreases the peak value of tensile hoop stress under it because of greater martensitic phase transformation expansion in cooling process and smaller yield stress at low temperatures.

数值研究已被用来分析9Cr / 2.25Cr异种焊接转子在进行焊接和热处理时的应力分布，以帮助优化结构设计。内外圆柱表面上的模拟残余应力已通过实验数据验证。还研究了沿焊接中心线沿厚度方向的焊接残余应力的分布和演变。已经发现，盖焊缝中马氏体相变和标称热影响区的收缩引起的膨胀决定了外圆柱面上残余应力的分布。同时，马氏体相变和弯曲效应在环形结构中引起的膨胀是贯穿壁残余应力的演化和分布的原因。穿墙焊接残余应力的分布和峰值在焊缝高度达到一定值（此工作距内圆柱面的厚度大约为30％）后仍保持不变，这提供了在较短的时间内预测应力分布的可能性。同时，焊后热处理（PWHT）可以有效释放残余应力。因此，人们对焊接残余应力给予了更多关注。与2.25Cr焊缝填充剂相比，9Cr焊缝填充剂在新沉积的焊缝金属中产生更大的压缩环向应力，并降低了其下的拉伸环向应力峰值，这是因为冷却过程中马氏体相变扩展更大，而低温时的屈服应力较小。