预制裂纹对X70管线钢冲击韧性和断裂机制的影响  

Influence of Prefabricated Crack on Impact Toughness and Fracture Mechanism of X70 Pipeline Steel

作　　者：周天宇 于宇新 商学欣 桂乐乐[1] Zhou Tianyu;Yu Yuxin;Shang Xuexin;Gui Lele(China Special Equipment Inspection&Research Institute, Beijing 100029)

机构地区：[1]中国特种设备检测研究院,北京100029

出　　处：《中国特种设备安全》2024年第S01期71-75,共5页China Special Equipment Safety

基　　金：国家重点研发计划“典型材料长期服役复合损伤演化规律及表征预测技术”(2021YFC3001801);中国特种设备检测研究院内部项目“高钢级天然气管道焊接及检测评价研究”(2020内02)。

摘　　要：随着管线钢应用逐渐增加,预防裂纹的扩展研究作为管线钢结构性能的研究重点而备受学者关注。本试验采用疲劳方法预制裂纹缺口,利用示波冲击试验,测试其与常规V型缺口在不同温度下对X70管线钢韧性的影响。结果表明,相较于常规V型缺口冲击试验,预制裂纹缺口的韧脆转变温度提高了约44℃,更贴近GB/T 20801.2—2020《压力管道规范工业管道第2部分:材料》规定的最低使用温度,在温度值的确定上提供了科学参考。通过对预制裂纹扩展过程中特征参数和宏微观断口形貌的分析研究,结果表明,裂纹扩展随着温度降低表现出一定的规律性,为基于示波冲击试验预测断裂机制提供了一定的参考依据。With the gradual increase in the application of pipeline steel,the propagation research of crack prevention has attracted much attention as the research focus of pipeline steel structure performance.In this test,the fatigue method was used to prefabricate the crack notch,and the oscillographic impact test was used to test the effect of the prefabricated crack notch and the conventional V-shaped notch on the toughness of X70 pipeline steel at different temperatures.The results show that compared with the conventional V-notch impact test,the toughness and brittle transition temperature of the prefabricated crack notch is increased by about 44℃,which is closer to the minimum service temperature specified in GB/T 20801.2—2020 Pressure Piping Code—Industrial Piping—Part 2:Materials,it provides a scientific reference for the determination of temperature value.Through the analysis of the characteristic parameters and macro-microscopic fracture morphology during the prefabricated crack propagation process,the results show that the crack propagation reveals a certain regularity with the decrease of temperature,which provides a certain reference basis for predicting the fracture mechanism of oscillographic impact test.

关 键 词：高钢级管线钢 预制裂纹缺口 示波冲击试验 裂纹扩展 

分 类 号：X933.4[环境科学与工程—安全科学]