不同温度下X100管线钢的冲击韧性

Impact toughness of X100 pipeline steels at different temperature

通过对X100管线钢试件冲击示波曲线、冲击断口形貌的观察,对比分析了在温度20℃、-60℃及-80℃条件下试件的冲击性能,研究了冲击过程中裂纹的形核和扩展规律。结果表明,裂纹启裂及扩展功所表现出的韧脆特性与总冲击功不同。随试验温度降低,断口分层现象明显,断口分层小平台可提高试验钢的断裂韧性,片状夹杂物则促进了脆性断口的产生;随温度降低,裂纹的扩展路径呈直线化,且尖角状裂纹较多。

The impact properties of X100 pipeline steels is analyzed at 20℃,-60℃and-80℃ by impact instrumented curve and fractographs.The result indicates that impact toughness decreases with the decreasing of the testing temperature,while the ductile-brittle property expressed by crack initiation and propagation energy is different from the total energy.When the testing temperature is relatively low,the layered fracture is severe,the fracture toughness is promoted by the layered fracture flat,and the brittle fracture is promoted by the inclusions with flake shape;the propagation path is linearized and the cracks with cusp shape increase as the testing temperature decrease.