喷熔修形后的焊接接头残余应力有限元分析  

Finite element analysis of residual stress of welded joints modified by spray fusing

作　　者：赵小辉[1] 王东坡[1] 邓彩艳[1] 

机构地区：[1]天津大学天津市现代连接技术重点实验室,天津300072

出　　处：《焊接学报》2011年第7期55-58,115-116,共4页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(50805102)

摘　　要：采用Ni60合金粉末对Q235B钢焊态十字接头进行了氧—乙炔火焰喷熔处理,同时进行了高频疲劳试验.分析认为喷熔修形改善了焊接接头的几何外形.喷熔修形态十字接头在2×106循环周次下的疲劳强度比原始焊态提高了64.5%.基于氧—乙炔火焰喷熔工艺参数,采用ANSYS12.0软件对喷熔过程进行了热-应力耦合的有限元模拟,分析认为,焊缝和涂层表面的残余应力仍为拉应力,但是残余拉应力的大小和喷熔前原始焊态接头表层的残余拉应力相比略微减小.原始焊态接头表层的拉应力约为238 MPa,喷熔修形后喷熔层表面的残余拉应力约为182 MPa,即火焰喷熔使得焊接接头表层的残余应力降低了24%.In this paper,Ni60 alloy powders were used to improve the fatigue strength of cruciform joints of Q235B through modification of spray fusing.Test results showed that the section shape of welded joints can be improved by flame spraying.High cycle fatigue test results showed that 2×106 cycles offset fatigue strength of the welded joints spray fused by Ni60 increased by 64.5%.The thermal stress was simulated by the finite element（ANSYS12.0） based on spraying parameters.Simulation results show that,the residual stress of substrate material and coating layer is still tensile stress and compared with as-welded joints,the magnitude of tensile stress decreases slightly.The residual stress of as-welded and coating surface is about 238 MPa and 182 MPa respectively.Thus,the residual stress is decreased by 24% after spray fusing.

关 键 词：喷熔修形 疲劳强度 应力集中系数 残余应力 

分 类 号：TG115.28[金属学及工艺—物理冶金]