超声冲击处理工艺对Q345焊接热影响区残余应力的影响

发布时间：2018-03-29 08:52

本文选题：焊接残余应力　切入点：超声冲击处理　出处：《表面技术》2017年07期

【摘要】：目的降低Q345焊接热影响区的残余应力。方法假设Q345对接焊缝两侧热影响区对称位置的表面残余应力一致,并采用盲孔法测量进行验证。采用超声冲击设备对焊缝一侧热影响区进行不同工艺参数的冲击处理,并测量焊缝两侧的残余应力值。对比焊缝两侧残余应力大小,并以消减率评价残余应力的消除效果。结果焊缝两侧热影响区对称位置的表面残余应力差值不超过最大主应力值的7.5%。超声冲击处理使热影响区的表面拉应力转变为压应力,消减率达到88%~130%。冲击时间一定,冲击电流的增大使残余应力消减率增大,但消减率增加的趋势变小。冲击电流一定,冲击时间增大时,残余应力的消减率变化不明显。结论可以认为焊缝两侧热影响区对称位置的应力值相等。提高冲击电流能够提高冲击力,使热影响区发生更大的塑性变形及位错结构变化,进而提高残余应力的消减率。但由于加工硬化的影响,消减率增加的趋势减小。超声冲击电流一定时,冲击力是一定的,提高冲击时间对消除率并没有明显的影响。
[Abstract]:Objective to reduce the Q345 welding residual stress of HAZ. Hypothesis Q345 butt weld heat affected zone on both sides of the surface residual stress of the symmetrical position, and blind hole method is used for measuring verification. The ultrasonic peening equipment of different process parameters on the weld heat affected zone on the side of the shock treatment, and residual stress measurement on both sides of the weld the value of residual stress. Comparing the weld size, and to reduce the rate of elimination effect evaluation of residual stress. The weld heat affected zone of surface residual symmetrical stress difference does not exceed the maximum principal stress value of 7.5%. ultrasonic impact treatment made HAZ surface tensile stress into compressive stress reduction rate of 88%~130%. impact time, increase the impact current of the residual stress reduction rate increases, but the reduction rate increased smaller. The impact of current, the impact time increases, the residual stress The elimination rate did not change significantly. Conclusion the weld heat affected zone stress values are equal. Improve the symmetrical position of the impulse current can improve the impact force, the heat affected zone of plastic deformation and dislocation structure of greater change, so as to improve the rate of reduction of residual stress. But due to the influence of work hardening, cut the rate of increase decreased. Ultrasonic impact current and impact is certain, improve the impact time and had no obvious effect on the removal rate.

【作者单位】：江苏徐州工程机械研究院;徐工集团工程机械有限公司高端工程机械智能制造国家重点实验室;徐州徐工挖掘机械有限公司;
【分类号】：TB559;TG404

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