快捷货车转向架用Q345E钢板焊接接头疲劳性能研究

快捷货车转向架用Q345E钢板焊接接头疲劳性能研究 Research on fatigue property of the welded joints of Q345E steel plate for express freight car bogie 魏世同 WEI Shitong 1 first-author 姜海昌 JIANG Haichang 1 陆善平 LU Shanping 1 中国科学院金属研究所沈阳材料科学国家研究中心 中国科学院金属研究所沈阳材料科学国家研究中心 Shenyang National Laboratory for Materials Sciences,Institute of Metal Research,Chinese Academy of Sciences Shenyang National Laboratory for Materials Sciences,Institute of Metal Research,Chinese Academy of Sciences 采用熔化极非惰性气体保护电弧焊(MAG)工艺对快捷货车转向架用Q345E钢板进行焊接试验,经无损检测合格后对焊接接头进行疲劳性能试验,制定了焊接接头的疲劳S-N曲线,并采用升降法确定了接头的疲劳极限及标准偏差,通过对疲劳试样断口进行系统分析,确定了接头的疲劳失效机制,结果表明:接头焊缝内的微小气孔和夹渣缺欠对接头的疲劳性能有明显影响,该缺欠在接头疲劳试验过程中将成为疲劳裂纹的萌生位置,进而恶化接头的疲劳性能。 Q345E steel plates for express freight car bogie were welded by metal active gas arc welding（MAG） welding method. After post weld nondestructive testing,the fatigue performance tests of the qualified welded joints were carried out. According to the test results,the fatigue S-N curve of the welded joint was drawn up,the fatigue limit and standard deviation of the welded joint were determined by lifting method. The fatigue failure mechanism of the welded joints was determined by fracture surface analysis of fatigue specimens.The results show that the porosity and slag defects in the weld have significant impacts on the fatigue properties of the welded joints,which will become the initial positions of fatigue cracks and deteriorate the fatigue properties of the welded joints. 富氩基CO2焊 疲劳极限 S-N曲线 扫描电镜 疲劳断口 argon-rich CO2 welding fatigue limit S-N curve scanning electron microscope fatigue fracture surface U272;TG407 国家重点研发计划资助项目(2017YFB1201302) 2022-03-08 1 50