Evaluation of fracture toughness in different regions of weld joints using unloading compliance and normalization method
Evaluation of fracture toughness in different regions of weld joints using unloading compliance and normalization method
复制标题
采用卸载柔度和归一化方法评估焊接接头不同区域的断裂韧性
DOI：
10.1016/j.engfracmech.2018.03.022
复制
发表时间：
2018-05-15
影响因子：
5.4
通讯作者：
Chen, Xu
中科院分区：
文献类型：
--
作者：
Tang, Jiankai;Liu, Zheng;Chen, Xu
对API5L X70和X80管线钢进行了ASTM E1820-16中规定的卸料柔度法和正火方法。对焊接接头不同区域的断裂韧性进行了广泛的实验测量。为了进行对比，将归一化方法测得的J-R曲线和起裂断裂韧性与弹性卸载柔度法测得的结果进行了比较。结果表明，两种方法具有较好的一致性，平均误差小于10%。对比表明，卸载柔度法的J-R曲线在裂纹扩展初期较低，而随着裂纹的扩展，J-R曲线较正则化法高。对于不同区域的焊接接头，两种方法得到的结果有明显的差异。焊缝金属与粗晶热影响区存在韧脆混合断裂机制，且有较大偏差。
Both unloading compliance method and normalization method specified in ASTM E1820-16 were conducted on the API 5L X70 and X80 pipeline steels. Extensive experimental measures of fracture toughness for different regions of weld joints were carried out. For comparison, the J-R curves and initiation fracture toughness determined using the normalization method are compared with those obtained by the elastic unloading compliance method for two different weld joints. The results show that good agreements exist between the two methods, and an average difference less than 10% is detected. Moreover, the comparison indicates that the J-R curves from the unloading compliance method are lower at the initial stage of crack extension, and as the crack grows, the J-R curves are higher compared with those of the normalization method. For different regions in weld joints, there is clear distinction of differences between the corresponding results from above two methods. A ductile brittle mixed fracture mechanism is found in weld metal and coarse grained heat affected zone, and a corresponding higher deviation is detected.