摘要
基于焊后热处理可以降低T91钢焊接残余应力,但无法改变其应力状态的分布问题,本文模拟分析了冲击法对于改善焊接残余应力的影响情况。通过ANSYS软件平台,导入经焊后热处理后的残余应力为初始状态,分析了不同的冲击力度、冲击间隔、双点冲击情况对于T91钢中小径薄壁管焊接残余应力的影响。模拟结果表明:冲击处理可以在处理表面一定深度范围内引入一定区域占比的压应力,并且压应力区域随载荷的增加而加大;由于不经焊后热处理的最高应力集中在焊缝内表面区域,因此只通过冲击处理的机械方式不能得到良好的改善焊后残余应力效果。通过焊后热处理结合焊缝区外表面冲击处理,可以在降低焊接残余应力的同时引入一定比例的压应力,从而得到较好的应力状态。单点环向冲击间隔7.2°的0.2mm冲击位移载荷下,具有75%左右的外表面环向压应力产生,可作为改善T91钢中小径薄壁管焊接残余应力的方案。
Based on the fact that post-weld heat treatment can reduce the welding residual stress of T91 steel tube, but the distribution of the stress can't be changed, the influence of impact treatment on welding residual stress is simulated and analyzed. The initial state of the residual stress occurred after post-weld heat treatment is introduced, the influences of different impact strength, impact interval and double point impact on the welding residual stress of medium and small diameter thin-wall T91 steel tubes, are analyzed based on the ANSYS software platform. The simulation results show that, the impact treatment can introduce a certain area of compressive stress in the depth range of the treated surface, and the compressive stress region increases with the increase of the load. Since the maximum stress without heat treatment concentrates in the inner surface area of the weld, the impact of the mechanical treatment is not a proper way to improve the residual stress after welding effect. The post-weld heat treatment combined with the impact treatment of outer surface of the weld zone can reduce the residual stress at the same time it introduces a certain proportion of compressive stress, resulting in a better stress state. The single point ring impact interval 7.2 o under 0.2 mm impact loading bring about 75% compressive stress in outer surface circumferential, which can be used as a scheme to improve the welding residual stress of medium and small diameter thin-wall T91 steel tubes.
出处
《应用力学学报》
CAS
CSCD
北大核心
2018年第5期950-955,共6页
Chinese Journal of Applied Mechanics
基金
国家自然科学基金(11372074)
福建省质量技术监督局科技计划项目(FJQI2012016)
关键词
T91钢
残余应力
冲击处理
数值模拟
应力改善
T91 steel
residual stress
impact treatment
numerical simulation
stress improvement
