约束控制对特厚板20MnNiMo钢焊接残余应力的影响

Effect of constrained control on residual stress in submerged-arc welds of thick plate 20MnNiMo joints

以热-弹塑性理论为基础,建立了100 mm厚20MnNiMo三维焊接有限元模型,利用ANSYS有限元程序分析了4种约束方式对特厚板焊接残余应力的影响,并通过盲孔法对部分模拟结果进行了试验验证.计算结果表明,约束位置的增加可以使焊接接头残余应力变大.随着约束位置的增加,焊缝区横向应力和热影响区纵向应力由压应力变成拉应力.约束位置越多,残余应力越大,焊接变形越小.模拟结果中,方案A试板边部翘曲变形最大,总变形量为39 mm,方案D变形最小,变形量为0.8 mm.

A three-dimensional finite-element model of welding residual stresses of thick plate in submerged arc welding for 100 mm thick 20MnNiMo steel was proposed based on the theory of thermal-elastoplasticity. Using ANSYS finite-element code, the effect of four external restraint on welding residual stresses of plate was analyzed. The temperature correlation of thermal physical property parameters with mechanical property parameters was considered during the simulation. The results show that increase in constraint position can make larger residual stress of welded joints. With the increase in binding position, the longitudinal stress of the weld zone and heat affected zone changed from the compressive stress into tensile stress. The more the number of location constraints, the greater the value of residual stress and the smaller the amount of welding distortion. The simulation results show that the largest warpage occurs in A test plate edge, and the total deformation is 39 mm; the least warpage occurs in D test plate edge, and the total deformation is 0.8 mm.