基于有限元反演方法的25Cr2Ni2MoV钢焊接接头疲劳失效分析  

Fatigue Failure Analysis of 25Cr2Ni2MoV Steel Welded Joints Based on Finite Element Inversion Method

作　　者：郭素娟[1] 罗甘霖 金鑫 司俊[3] GUO Sujuan;LUO Ganlin;JIN Xin;SI Jun(School of Mechanical and Power Engineering,East China University of Science and Technology,Shanghai 200237,China;China Nuclear Power Technology Research Institute Co.,Ltd.,Shenzhen 518028,China;Shanghai Institute of Special Equipment Inspection and Technical Research,Shanghai 200062,China)

机构地区：[1]华东理工大学机械与动力工程学院,上海200237 [2]中广核研究院有限公司,广州深圳518028 [3]上海市特种设备监督检验技术研究院,上海200062

出　　处：《热加工工艺》2025年第5期56-61,共6页Hot Working Technology

基　　金：国家自然科学基金项目(11872181)。

摘　　要：以25Cr2Ni2MoV钢焊接接头为对象,开展了不同应变幅水平下的低周疲劳试验,得到了其低周疲劳强度特征,并对失效试样的疲劳失效位置进行了规律统计。结合纳米压痕试验和有限元反演方法,获取了焊接接头不同区域的力学性能对比和相关参量,反演出其母材、焊缝和热影响区3个区域的应力-应变曲线,同时采用有限元方法得到了焊接接头的局部轴向应变分布特征,揭示了焊接接头疲劳失效位置随载荷水平变化的演化机理。结果表明:在较低的应变水平下,焊接接头的最大轴向应变主要集中在靠近热影响区的母材,低周疲劳失效位置也集中在这里;当载荷水平居中时,热影响区附近母材和焊缝中心轴向应变相当,低周疲劳失效位置在两处随机出现;当载荷水平较大时,最大轴向应变出现在焊缝中心处,疲劳失效位置也主要出现在焊缝中心处。Taking the 25Cr2Ni2MoV steel welded joint as the object,the low cycle fatigue experiments were carried out at different strain levels to obtain the low cycle fatigue strength characteristics,and the fatigue failure locations of the failed specimens were counted.Combined with the nanoindentation experiment and finite element inversion method,the mechanical properties of different regions of the welded joints were compared and the relevant parameters were obtained.Also,the stress-strain curve of the three regions including the base metal,the weld metal and the heat-affected zone was inversed.At the same time,the local axial strain distribution characteristics of the welded joint were obtained by finite element method,and the evolution mechanism of fatigue failure location of the welded joint changing with load level was revealed.The results show tht at low strain levels,the maximum axial strain of the welded joint is mainly concentrated in the base material near the heat affected zone(HAZ),and the low cycle fatigue failure locations are also concentrated here.When the load level is medium,the axial strain of the base material and the weld near the HAZ is equivalent,and the low cycle fatigue failure position appears randomly in the two places.When the load level is large,the maximum axial strain appears at the weld center,and the fatigue failure position is also mainly present in the weld center.

关 键 词：焊接接头 低周疲劳 失效机理 纳米压痕 有限元方法 

分 类 号：TG115.57[金属学及工艺—物理冶金] TG142.33[金属学及工艺—金属学]