采用X射线应力分析仪和电子背散射衍射仪(EBSD)等分别研究了热处理前后20G钢焊接接头的表面残余应力和微区残余应力.结果表明:热处理前后焊接接头的表面残余应力均以焊缝为中心呈对称分布,且随距焊缝中心距离的增大而下降,热处理后的平均残余应力比热处理前的降低了7.21%;热处理后焊接接头焊缝区、热影响区和母材区的晶粒发生再结晶转变,晶粒得到细化;再结晶导致局域取向错配角的平均值减小,微观残余应力得到释放,且分布更为均匀,但焊缝区的微观残余应力依然较高.%Surface residual stresses and micro-residual stresses in 20G steel welded joint before and after heat-treatment were studied by X-ray stress analyzer and electron backscattered diffractometer (EBSD),respectively. The results show that the surface residual stresses distributed symmetrically along the weld center and decreased with increasing distance from the weld center.The average residual stress of the joint after heat-treatment was lower by 7.21% than that before heat-treatment.After heat-treatment,the recrystallization of the grains occurred in the weld zone,heated affected zone and base metal of the welded joint,resulting in the refinement of the grains.The kernel average misorientation values decreased,and the micro-residual stresses were released and distributed evenly due to the recrystallization.However,the micro-residual stresses in the weld zone were still relatively high.
展开▼
