基于焊接的UIC900A及U75V钢轨钢的连续冷却特性  

Characteristics of Continuous Cooling of UIC900A and U75V Rail Steel for Welding

作　　者：刘丰收[1] 张银花[2] 陈朝阳[2] 周清跃[1] 

机构地区：[1]铁道科学研究院铁道科学技术研究发展中心,北京100081 [2]铁道科学研究院金属及化学研究所,北京100081

出　　处：《中国铁道科学》2005年第6期63-68,共6页China Railway Science

基　　金：铁道部科技研究开发计划项目(2001G017)

摘　　要：模拟钢轨焊接及焊后热处理工况,采用热膨胀方法分别测定UIC900A及U75V钢轨钢的连续冷转变曲线(CCT曲线).通过对UIC900A及U75V钢轨钢连续冷却特性的分析和比较,结果表明:当模拟焊接的奥氏体化温度为1 300℃和冷却速度小于1.5℃·s-1时,这2种钢轨钢的组织均为珠光体,并且在正常情况下焊接后直接空冷也都不会出现马氏体组织,这时UIC900A和U75V钢轨钢的硬度分别达到329 HV和354 HV;当模拟焊后热处理的奥氏体化温度为900℃和冷却速度为0.5℃·s-1时,这2种钢轨钢的硬度均为300 HV左右.UIC900A钢轨钢可直接空冷,U75V钢轨钢则需用冷却速度为1～2℃·s-1的喷风软淬火,以使其硬度达到320～350 HV左右.By simulating welding and simulating heat treatment after welding, CCT Curves of UIC900A and U75V rail steels are determined by the expansion method. The results of simulating welding CCT curves show that the microstructure of two rail steels are pearlite when austenitizing temperature is 1300 ℃ and cooling rate is under 1.5 ℃·s^-1, there is no martensite when the rails are normally cooled in air after welding, and the hardness of UIC900A and PD3 are 329 HV and 354 HV respectively. The simulating heat treatment after welding CCT curve shows that when austenitizing temperature is 900 ℃ and cooling rate is 0.5 ℃·s^-1, the hardness of two rail steel are about 300 HV. UIC900A can be cooled in air and the cooling rate of U75V should be 1.0-2.0℃·s^-1 in order to make the hardness of two rail steels reach about 320-350 HV.

关 键 词：钢轨钢 CCT曲线 焊接 连续冷却特性 

分 类 号：U213.41[交通运输工程—道路与铁道工程]