摘要
残余应力在焊接构件中普遍存在,不均衡分布的残余应力是构件变形和开裂的根源,直接影响焊接构件的承载能力、稳定性和服役寿命。焊接残余应力随构件服役环境及外界载荷变化而动态分布,对残余应力的消减、均化应贯穿焊接构件设计、生产和服役全生命周期。焊接变形及残余应力控制关键在于塑性区的调控,合理的焊接顺序能有效降低工件应力集中并改善其分布状态,及时的焊前预热及焊后回火能有效降低接头温度梯度、松弛应力集中、消减残余应力。对焊缝的锤击松弛处理能抵消部分焊缝区收缩,减小残余拉应力。对焊缝及周边区域施加拉伸、振动时效、超声冲击和喷丸强化等力学形变载荷,可与焊件内部应力叠加促进塑性形变,释放、均衡残余应力。这些方法各有优势,但均需密切结合构件材料、结构及性能控制要求来进行选择。随着制造业转型发展及绿色环保政策驱动,未来工程装备残余应力调控技术会向绿色环保、柔性高效、过程可控、专业化方向转变。
Residual stress is widespread in welded components.Uneven distribution of the residual stress is the source of deformation and cracking of structural parts,which directly affect the bearing capacity,stability andservice life of welded components.The residual stress of welding is distributed dynamically with the change of service environment and external load.The reduction and homogenization of residual stress should be carried through the entire life cycle of welding component design,production and service.The key to controlling deformation and residual stress in welding lies on the regulation of the plastic zone.A well-performed welding sequence can effectively reduce the residual stress after welding and improve its distribution.Proper preheating before welding and tempering after welding can effectively reduce temperature gradient,relax stress concentration,and reduce residual stress at the joint.The hammering treatment of the welded joint can extend the metal to offset part of the shrinkage in the welding area,which reduces the residual tensile stress.In the mechanical deformation method,load is applied on the weld and the surrounding area,and then the external load and the internal residual stress are superimposed to make the component undergo plastic deformation.The plastic deformation allows the residual stress to be released and balanced.The common mechanical deformation methods include tensile strength,vibration aging,explosion treatment,ultrasonic impact and shot peening strengthening.Each mechanical deformation method has its own advantage,thus,they should be carefully selected considering the component materials,structure,and performance control requirements.Driven by the transitional development of manufacturing industry and the environmental protection policies,the residual stress regulation technology is expected to be greener,more flexible and efficient,more controllable and specialized in the future.
作者
郭政伟
龙伟民
王博
祁婷
李宁波
GUO Zhengwei;LONG Weimin;WANG Bo;QI Ting;LI Ningbo(Shanghai Aerospace Equipments Manufacture Co.,Ltd.,Shanghai 200245,China;China Innovation Academy of Intelligent Equipment Co.,Ltd.,Ningbo 315700,Zhejiang,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2023年第2期144-150,共7页
Materials Reports
基金
河南省重大关键技术需求揭榜攻关项目(191110111000)
宁波市“3315”人才计划2020年创新团队C类。
关键词
焊接残余应力
焊接顺序
热时效
超声冲击
脉冲磁场
welding residual stress
welding sequence
thermal aging
ultrasonic shock
pulsed magnetic field
