振动时效法消除SMA490BW耐候钢焊接残余应力研究

Research on the residual stress of SMA490BW atmospheric corrosion resistant steel treated by vibratory stress relief

对SMA 490BW耐候钢进行MAG焊接,利用振动时效设备对焊件进行振动时效处理,并通过盲孔法测试和分析振动时效处理前后试件的残余应力。对振动时效处理后的应力消除效果进行评估发现应力消除效果不佳。为排除偶然误差,再次进行振动时效处理并测试其应力值。两次实验后均发现试件焊缝区残余应力较大,经过振动时效处理后应力有所下降,但其应力消除率仅为百分之十几。分析了导致消应力效果不佳的原因,并得出结论:对于大尺寸、厚重焊接件去应力效果良好的振动时效法应用于小尺寸、质量轻的焊接件效果不甚理想,应考虑采用超声冲击等方法。

Gas shielded welding was done on SMA 490 BW atmospheric corrosion resistant steel and vibratory stress relief treatment was made to the weldments.The residual stresses were tested and analyzed before and after vibratory stress relief treatment by adopting blind-hole method.It doesn＇ t have a good effect on releasing residual stresses after stress relief treatment.The test specimens were treated by vibratory stress treatment and then the residual stresses were tested again for the purpose of getting rid of accidental error.There is a group of larger residual stresses in the weld zone in both experiments.The residual stresses decreased lightly after the vibratory treatment,but the stress eliminating rate is only 10-odd percent.The possible reasons causing to the unsatisfied effect of releasing residual stresses are analyzed in the paper and a conclusion comes to us that the vibratory stress relief treatment works well on releasing residual stress of those heavy and large-sized work pieces,while hardly on light or small-sized ones.So the methods like the ultrasound impact treatment may be much better.