核电SA508-3钢厚壁圆筒纵向焊接残余应力分析

针对由某公司生产首次应用到核电设备上的SA508-3钢,为了获得焊接残余应力分布及规律,采用ANSYS有限元软件对60 mm厚圆筒纵焊的焊接接头进行温度场及残余应力数值模拟,并将模拟结果与相同工艺条件下焊接试验结果进行比较验证.结果表明,模拟结果与试验结果基本吻合;焊接时热源周围极窄区域温度高,梯度大,远离热源温度峰值急剧下降;圆筒外表面残余应力大于内表面残余应力;焊缝及近焊缝区的残余拉应力值较大,远离焊缝中心残余拉应力值逐渐减小;圆筒两端和中部的残余应力在方向上或数值大小上不同;这对控制圆筒残余应力提供了理论依据.

Numerical simulation and experiments test of residual stress of longitudinal weld of thick SA508-3 steel pipe for nuclear power

Welding process of 60 mm thick SA508-3 steel pipe which is firstly used in nuclear power was simulated by ANSYS to obtain the temperature field and the residual stress.Simulated thermal and mechanical results were compared with the experimental results in the same welding parameters.It was found that the residual stress distribution is close to the measured values.During welding,the peak temperature exists in the centre of the heat source and its vicinity where the temperature gradient is much larger.However,the temperature descends sharply away from heat source.The residual stress on the outer surface of pipe are greater than that in the inner surface,of which the tensile residual stress in the welding zone and adjacent zone are largest,and gradually decreases away from the welding zone.The residual stress in the middle of cylinder is opposite to that in the two longitudinal ends.These results provide theoretical knowledge for the control of welding residual stress of pipe.