X80钢大口径螺旋焊管的残余应力

Residual Stress of X80 Large-Diameter SAWH Pipe

采用盲孔法和切环法对不同成型参数的X80钢大口径螺旋焊管的残余应力进行了测试,并对其残余应力的水平、分布特点及产生的原因进行了分析。结果表明:X80钢大口径螺旋焊管残余应力表现形式复杂多样,其残余应力的分布及水平反映了螺旋焊管成型时成型参数的设置;其峰值残余应力均出现在焊缝区内表面;切环试验的内插变形是成型时压下量过大造成内表面的残余拉应力比外表面的残余拉应力大所致。

Residual stress of X80 large-diameter SAWH pipe with different forming parameters were examined by blind hole drilling method and slit-ring method, then the residual stress level and distribution and cause were analyzed. The results show that the residual stress of X80 large-diameter SAWH pipe was complicated and the distribution and level of residual stress reflected the forming parameters during forming of X80 SAWH pipe. The peak residual stress appeared at the inner surface of weld seam zone of the X80 large-diameter SAWH pipe. The over lapping deformation in the slit-ring test was due to extra press value, which resulted in the residual tensile stress on inner surface was larger than that on outside surface.