论文部分内容阅读
青藏铁路等低温地区铁路的建设与维护,对钢轨铝热焊接接头的低温力学性能的研究提出了迫切的要求.通过U71Mn和U75V两种钢轨的铝热焊接接头低温拉伸试验,得到了两种钢轨铝热焊接接头各温度下的强度与塑性指标,分析了各指标随温度的变化规律.结果表明,两种钢轨铝热焊接接头的规定非比例延伸强度均随温度的降低而提高,而抗拉强度均随温度的降低而降低;两者的屈强比均随温度的降低而升高,断后伸长率和断面收缩率均随温度的降低而减小,塑性变差,低温冷脆倾向增加;U71Mn钢轨接头的断后伸长率和断面收缩率均较U75V钢轨接头大,塑性更好.在寒冷地区的铁路建设中,宜优先选用U71Mn钢轨及相应的铝热焊接材料.
Qinghai-Tibet Railway and other low temperature areas of the railway construction and maintenance of the rail aluminum welded joints at low temperature mechanical properties of the research put forward urgent requirements.Through the U71Mn and U75V two kinds of rail aluminum welded joints at low temperature tensile test, obtained two The results show that the non-proportional extension strength of the aluminum heat welded joints of both rails increases with the decrease of temperature, while the resistance The tensile strength decreases with the decrease of temperature. The yield strength ratio of both increases with the decrease of temperature. The elongation at break and the reduction of area decrease with the decrease of temperature, the plasticity deteriorates, Increase.The elongation at break and reduction of area of U71Mn rail joint are larger than U75V rail joints and better plasticity.U71Mn rail and the corresponding aluminum thermal welding material should be preferred in the railway construction in cold area.