SMA490BW耐候钢TIG焊接接头残余应力分析  

Residual stress analysis of TIG welded joints of SMA490BW weathering steel

作　　者：马龙 Ma Long(CRRC Qingdao Sifang Co.,Ltd.,Qingdao 266111,Shandong,China)

机构地区：[1]中车青岛四方机车车辆股份有限公司,山东青岛266111

出　　处：《焊接》2024年第6期68-73,80,共7页Welding & Joining

摘　　要：【目的】旨在进行SMA490BW耐候钢TIG焊接接头疲劳寿命的评估。【方法】采用盲孔法、X射线法、有限元分析3种方法对SMA490BW耐候钢TIG焊接接头进行了焊接残余应力分析,并对切割小试样引起的残余应力变化进行分析。【结果】结果表明,SMA490BW耐候钢纵向残余应力在焊缝拉应力峰值接近材料屈服强度,远离焊缝中心残余应力迅速降低并进一步转变为压应力,此分布规律为典型的纵向残余应力分布特征。在整体试板上采用线切割出用于疲劳试验的足尺寸小试样,小试样上纵向残余应力的峰值接近230 MPa,约为屈服强度的70%,纵向残余应力在横向分布规律保持不变。【结论】该部分所建立的有限元模型分析结果与测试数据吻合很好,证实模型的热源模型、力学边界条件均与实际工艺接近,采用该计算模型的精度和正确性可以保障。[Objective]The purpose was to evaluate fatigue life of TIG welded joints of SMA490BW weathering steel.[Methods]Three methods,namely blind hole method,X-ray method and finite element analysis,were used to analyze welding residual stress of TIG welded joints of SMA490BW weathering steel,and changes of residual stress caused by cutting small specimens were analyzed.[Results]The results showed that longitudinal residual stress of SMA490BW weathering steel approached yield strength of material at the peak tensile stress in weld,and rapidly decreased and further transformed into compressive stress away from the center of weld.This distribution pattern was a typical characteristic of longitudinal residual stress distribution.Full size small specimens were cut by wire cutting on the overall test panel for fatigue testing.The peak value of longitudinal residual stress on small specimens was close to 230 MPa,which was about 70%of yield strength.Transverse distribution pattern of longitudinal residual stress remained unchanged.[Conclusion]Analysis results of this finite element model established in this section were in good agreement with test data,it was confirmed that the heat source model and mechanical boundary conditions of the model were close to actual process.Accuracy and correctness with this calculation model could be guaranteed.

关 键 词：SMA490BW耐候钢 残余应力 盲孔法 有限元法 X射线法 

分 类 号：TG404[金属学及工艺—焊接]