工作温度对TP2铜管组织与性能的影响规律研究

Effect of Working Temperature on Microstructure and Properties of TP2 Copper Tube

高速列车车顶用TP2铜管常年在-30~100℃露天环境下服役,为探究中低工作温度区间内TP2铜管组织与性能变化,测试、观察了TP2铜在-30~100℃下的硬度、拉伸性能、金相组织断口形貌,结果表明:在-30~100℃温度区间内,随温度升高,TP2铜管晶粒增大,晶粒度由8.95降至8.02,下降幅度为10.39%;硬度随温度升高逐渐降低,变化幅度为5.64%;抗拉强度由263.25 MPa下降至217.09 MPa,下降幅度达17.53%;平均延伸率均保持在50%以上;断口存在大量韧窝,断裂形式为韧性断裂。

TP2 copper tubs used for the roof of high-speed trains are usually in service in open-air environment all year round,with the working temperature ranging from-30℃to 100℃.In order to explore the effect of low-to-medium temperature range on the microstructure and properties of TP2 copper tube,the microstructure,hardness,tensile properties and fracture morphology of metallographic structure in TP2 copper tube at different temperature were tested.Within the working temperature ranging from-30 to 100℃,the results showed that the grain size of TP2 copper tube increased by increasing the temperature,with the grain numbers decreased from 8.95 to 8.02,down by 10.39%;the hardness decreased gradually with the increase of temperature,by just 5.64%;the tensile strength decreased from 263.25 MPa at-30℃to 217.09 MPa at 100℃,a 17.53%decrease;the average elongation maintained above 50%;a large amount of dimples were observed in the fracture,indicating that it was ductile fracture.