三维管接头焊后局部热处理加热宽度准则

提出了直接定量评定管接头焊后局部热处理应力释放效果的方法。构造了三维管接头焊接应力和局部热处理温度场，采用粘弹塑性有限元方法对管接头焊后不同局部热处理条件不应力分布特征进行了研究，对单道焊情况，不同焊接规范下的焊接应力分布具有相似性，焊接顺序对应力峰值位置的影响较小。对管接头热点处焊接应力在不同局部热处理条件下释放程度做了分析，在局部热处理加热宽度足够大情况下残余应力明显下降，周向和轴向应力分量与加热宽度的关系不同，周向和轴向应力的最优加热宽度分别为3.46√-Rr的4.8√-Rt。通过对局部热处理主要工艺参数的计算，推荐了正交管接头局热处理加热宽度准则。

Heated Band Width Criterion in Local Post Weld Heat Treatment of Three Dimensional Tubular Joint

A direct quantitative method has been proposed to assess the effectiveness of stress relief for tubular joint in local post weld heat treatment(PWHT). The three dimensional welding residual stress and temperature fields in local PWHT are constructed. The characteristics of stress distribution in local PWHT for tubular joints have been studied using visco elastic plastic FEM. The welding stress distributions in single pass welding of different welding condition are quite similar. The different welding sequences don't have much influence on the location of the peak value stress. The degree of welding stress relief in hot spots of tubular joint under different condition of local PWHT has been analyzed. The residual stress is greatly lessened with increase of the heated band width in local PWHT. The relations between the heated band width and the stress of circumferential and axial components are quite different,the optimum heated band widths for circumferential and axial component are 3. 46 Rt and 4. 8 Rt. With computation of main processing parameters in local PWHT,a criterion of heated band width has been recommended for the concurrent tubular joint in lcoal PWHT.