铸态下具有-40℃冲击韧性的QT500-7AL齿轮箱熔炼工艺研究

摘要

HXD3C型交流传动电力机车是我国铁路线上主力机型之一,其关键的走行部分驱动装置齿轮箱体铸件的材质由QTS00-7升级为QT500-7AL,要求具有-40℃低温冲击.通过合理的化学成分设计及铁水球化孕育处理工艺研制成功铸态下具有-40℃冲击韧性的QT500-7AL齿轮箱,其抗拉强度可达500～530MPa,伸长率可达10％ ～20％,-40℃冲击值可达7～9J.%The HXD3C AC drive electric locomotive is one of the main models on the railway line in China.The material of key walking parts for the driving gear box body castings have been upgraded from QT500-7 to QT500-7AL,which has been required to stand a low temperature shock of-40℃.The QT500-7AL gearbox with impact toughness of-40℃ under as-cast condition has been successfully developed through reasonable chemical composition design and hot metal ball inoculation treatment process.Its tensile strength can reach 500-530MPa and its elongation can reach 10％～20％,while the impact value of-40℃ can be up to 7～9J.