论文部分内容阅读
采用等离子束焊(PBW)和钨极惰性气体保护焊(TIG)方法对大口径镍铬合金石油管道环焊缝进行打底焊接,采用数值模拟方法分析了两种打底焊接工艺下,焊缝及其邻近区域的温度场、残余变形和残余应力的分布。数值模拟时,根据两种焊接工艺的热源特点,选用不同的热源模型进行计算;同时考虑了材料热物理性能与温度的非线性关系,以及相变潜热对温度场的影响。结果表明,采用PBW能够得到深而窄的焊缝截面,残余应力和残余变形都比TIG打底焊缝小。
Plasma welding (PBW) and tungsten inert gas shielded arc welding (TIG) were used to make backing weld on the large caliber Ni-Cr alloy oil pipeline girth weld. The numerical simulation method was used to analyze the weld seam And its adjacent areas of the temperature field, residual deformation and residual stress distribution. According to the characteristics of the heat sources of the two welding processes, different heat source models are used in the numerical simulation. The nonlinear relationship between the thermophysical properties of the materials and the temperature and the influence of the latent heat of phase transformation on the temperature field are also considered. The results show that the deep and narrow weld cross section can be obtained by using PBW, the residual stress and residual deformation are smaller than the TIG weld.