高铁用U75V钢轨钢动态CCT曲线  

Dynamic CCT Curve of U75V Steel for High-Speed Railway

作　　者：李波[1] 朱国明[1] 陶功明 康永林[1] 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083 [2]攀钢集团攀枝花钢钒有限公司,四川攀枝花617000

出　　处：《钢铁研究学报》2014年第11期20-24,共5页Journal of Iron and Steel Research

摘　　要：用膨胀法结合显微组织观察及硬度测量方法,得到了U75V钢轨钢动态CCT曲线。结果表明：当冷却速度为0.05-3℃/s时的U75V钢轨钢的显微组织为珠光体组织,而且随着冷却速度的加快珠光体片层间距逐渐减小;冷却速度为5℃/s时主要的显微组织为珠光体组织,但出现少量马氏体组织;当冷却速度为15-50℃/s时的显微组织为马氏体和残余奥氏体组织。随着冷却速度的增大,硬度呈增加趋势。高铁用U75V钢轨钢奥氏体向珠光体开始转变温度不超过700℃,相变结束温度不低于500℃,当冷却速度为2-3℃/s时珠光体片层间距最为细小。The expansion curves of continuous cooling transformation at different cooling rates of U75 Vsteel for sigh-speed railway were got by dilatometric change referencing microscopic test and hardness measurement.The results show that the product of austenite transformation is pearlite when the cooling rate is lower than 3 ℃/s,and the pearlite interlamellar spacing decreases as the cooling rate increasing.Pearlite and little martensite is obtained at the cooling rate of 5 ℃/s,martensite and retained austenite is got if the cooling rate is in the range of 15-50 ℃/s.The hardness of the steel increases with the increase of cooling rate.The starting transformation temperature from austenite to pearlite of U75 Vsteel for high-speed railway is less than 700 ℃,and the finishing transformation temperature is higher than 500 ℃.The pearlite has the minimum interlamellar spacing when the cooling rate is 2-3 ℃/s.

关 键 词：动态CCT 珠光体片层间距 显微硬度 显微组织 U75V钢 

分 类 号：TG142.1[一般工业技术—材料科学与工程]