在国内常用钢轨钢材及其铝热焊缝的低温拉伸试验结果的基础上,利用扫描电子显微镜分析各自的断口微观形貌,得出其破坏的微观机理,进而从断口形貌的角度解释钢轨钢材及其铝热焊缝的低温下抗断裂性能。研究结果表明钢材及焊缝低温下的脆性特征,其中,U71Mn要好于U75V钢材,而与钢材相比焊缝的韧性相对较差。
Basing on the results of the tensile test of rail steel and thermit welding which are popular domestically, this paper uses scanning electron microscope to analyze the fracture micro - morphology, finds the fracture microscopic mechanism, and lastly interprets the anti - fracture property at low temperature from fracture morphology viewpoint. The result shows the brittle feature of rail steel and welding at low temperature, among which U71Mn is better than U75V, and the welding is relatively worse than steel.