预拉伸对奥氏体不锈钢焊接残余应力影响的研究

Study on Effect of Pre Tensile on Welding Residual Stress of Austenitic Stainless Steel

奥氏体不锈钢应变强化技术是通过产生一定的塑性形变来提高材料的屈服强度从而达到节省材料的目的。为了保证安全,必须对焊接工艺试板预拉伸后再进行焊缝力学性能测试,试板中的焊接残余应力会对后续取样以及测试结果产生影响,因此受到关注。本文通过有限元数值模拟结合试验数据,得到焊接试板内的温度及残余应力分布,并模拟了预拉伸对焊接残余应力分布的影响,认为垂直焊缝方向的拉伸,可以有效释放焊接过程中产生的残余应力,并弱化了残余应力分布的不均匀性。

Plastic deformation was performed to austenitic stainless steel to increase yield strength, so that the cost of material decreases, which is called cold-stretch technology. To ensure safety, pre-tensile is needed before mechanical properties test is performed. The welding residual stress in test plate is concerned because it has an effect on the specimen machining and test results. The residual stress and temperature distribution in test plates for welding procedure were investigated by experiment and FEA, the effects of pre-tensile on residual stress distribution were simulated, so that we could think verticl pre-stretching can effectively release the welding residual stress and reduce the inhomogeneity of stress distribution,