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坡口角度对K形对接接头组织与疲劳性能的影响

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为解决Q450NQR1耐候钢K形坡口对接接头的坡口角度选择问题,以45°、50°、60°K形坡口对接接头为研究对象,对三种坡口角度的对接接头进行了金相、疲劳试验,分析阐述了坡口角度对接头金相组织分布与疲劳性能的影响;此外,通过对疲劳断口的扫描观察,分析了其断裂特征与机理.试验结果表明:各坡口角度对接接头各区域的组织成分相近,焊缝柱状晶粒宽度及粗晶区晶粒尺寸与坡口角度成正比;45°、50°、60°K形坡口对接接头的疲劳极限依次为151 MPa、147.5 MPa、135 MPa,疲劳极限与坡口角度成反比;疲劳试件断口启裂区和扩展区具有典型的疲劳断裂特征,扩展区存在较为明显的疲劳弧线,终断区可观察到典型的韧窝组织;坡口角度越大,扩展区疲劳弧线与终断区韧窝组织越稀疏.
Effect of Groove Angle on Microstructure and Fatigue Properties of K-butt Joint
In order to solve the problem of groove Angle selection of K groove butt joint of Q450NQR1 weathering steel,this paper takes 45°,50° and 60°K groove butt joint as the research object,metallographic and fatigue tests are carried out on the three kinds of groove Angle butt joint,and the influence of groove Angle on the metallographic distribution and fa-tigue performance of the joint is analyzed.In addition,the fracture characteristics and mechanism are analyzed by scanning observation of fatigue fracture.The test results show that the microstructure composition of the butt joint is similar in each area of the groove Angle,and the grain width of the weld column and grain size of the coarse-grain zone are proportional to the groove Angle.The fatigue limits of 45°,50°,60°K beveled butt joints are 151 MPa,147.5 MPa,135 MPa,and the fa-tigue limit is inversely proportional to the beveled Angle.The fracture initiation zone and the extension zone of the fatigue specimen have typical fatigue fracture characteristics,there is obvious fatigue arc in the extension zone,and the typical dimple structure can be observed in the final fault zone.The larger the Angle of the groove,the more sparse the fatigue arc and dimple structure in the extended zone.

Q450NQR1 weathering steelK-groovefatigue performancegroove angle

暴兴威、许鸿吉、宋睿、吴庆祝、刘楷

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大连交通大学 材料科学与工程学院,辽宁 大连 116028

Q450NQR1耐候钢 K形坡口 疲劳性能 坡口角度

2025

电焊机
成都电焊机研究所

电焊机

影响因子:0.39
ISSN:1001-2303
年,卷(期):2025.55(1)