机械应力消除法对焊接残余应力的影响

大直径全焊接阀体球阀制造的最后一道工序是焊接，由于采用橡胶圈密封，为防止密封圈的损坏，导致密封性能降低，焊后不能采用焊后热处理消除焊接残余应力。为了控制阀体焊接残余应力，选择机械应力消除法，建立阀体机械应力消除法的加载压力与时间的关系曲线，采用有限元分析和试验相结合的方法，研究机械应力消除法对焊接残余应力的影响。机械应力消除法前后采用盲孔法测量阀体外表面的残余应力。结果表明，采用二维轴对称有限元法可以模拟机械应力消除法过程，机械应力消除法可以降低阀体外表面轴向应力和环向应力的峰值，使残余应力分布更加均匀，可以作为焊后热处理的替代工艺。

Effect of Mechanical Stress Relieving Method on Welding Residual Stress

For big diameter full welded body ball valve,welding is the last process.Because it is sealed with rubber grommet,in order to prevent the grommet from damaging and assure the tightness,post-weld heat treatment(PWHT) method cannot be used to relieve the residual stress.Therefore,mechanical stress relieving method(MSR) is selected to control the welding residual stress of valve body and the relationship between load and time is established.The effect of mechanical stress relieving method on the welding residu...