横向载荷对含表面裂纹对焊接头疲劳裂纹扩展速率影响的研究

Research into the influence of horizontal loading on the fatigue crack extension rate of the butt joint with surface cracks

研究了双向载荷作用下对焊接头表面裂纹的疲劳扩展规律。采用经精确标定应力强度因子幅值的双向十字形试样,在电液伺服双轴向疲劳试验机上对母材分别为16MnR 和 Q235-B 这两种钢的对焊试板进行了疲劳裂纹扩展试验。同时,将其结果分别与单向应力下对焊接头及母材的疲劳扩展速率进行了比较,为制定我国在役压力容器缺陷评定规范提供了参考数据。

The fatigue extension law of the surface crack of butt joints under the bidirectional loading action was studied, and the fatigue crack extension experiments of butt welding test plates of 16MnR and Q235-B were conducted on a bi- axial fatigue testing machine with servoelectrolyte using a cross test sample indicating accurate stress strength factor values.A comparison was made between the result and the fatigue extension rates of the butt joints and their mother materials under one-directional stress,and a basis was pro- vided for the defect assessment codes of the Chinese pres- sure vessels in service.