二冷制度对高速列车车轮钢圆坯内部质量的影响  

Effect of secondary cooling schedule on internal quality of steel round billet for wheel of high speed train

作　　者：景财良[1] 王新华[1] 许志刚[1] 龚志翔[2] 王万军[1] 

机构地区：[1]北京科技大学冶金与生态工程学院,北京100083 [2]马鞍山钢铁有限公司技术中心,安徽马鞍山243000

出　　处：《炼钢》2011年第6期49-52,共4页Steelmaking

基　　金：国家863计划(2008AA030703)

摘　　要：为优化高速车轮钢大圆坯的内部质量,比较了2种二冷制度下,铸坯二冷段的表面温度、凝固组织与宏观偏析的区别。结果表明:2种二冷制度下的铸坯在矫直段的表面温度均高于900℃,处于车轮钢高温塑性区,可避免产生矫直裂纹;铸坯的等轴晶率差别不大,在过热度小于55℃的条件下,均得到了较对称的凝固组织与良好的内部质量;区别在于,制度1条件下的圆坯中心偏析较轻,中心缩孔较小,但是中心疏松面积较大,且沿半径方向上的偏析波动更为剧烈,对其之后的轧制和成品的质量更为不利,不适合用于高品质车轮钢的生产。In order to optimize the internal quality of round steel billet for the high-speed train wheel the differences among surface temperature, solidification structure and mac- rosegregation of casting billets under the two different secondary cooling schedules have been compared in this study. The results show that under both two cooling schedules the surface temperatures of the billets at the straightening segment are all higher than 900 ~C and thus the straightening cracks will avoid occur since the wheel steel is in such a high temperature zone at the time. The differential rate of equiaxed crystal ratio of the billets is of insignificance and under the condition of overheat less than 55 ℃both better symmetrical solidification structures and better internal quality of the billets are a- chieved. Difference lies in that under the condition of No. 1 cooling schedule the central segregation of the casting billets is lighter and central shrinkage smaller, however the area of central porosity is relatively larger and the fluctuation of segregation along the direction of upper radius tends to be more severe. It＇s disadvantageous for the roiling op- eration at the down stream as well as the quality of the finishing products. Therefore the No. 1 cooling schedule is not suitable for production of high quality wheel steel.

关 键 词：高速列车车轮钢 圆坯 二冷制度 凝固组织 宏观偏析 

分 类 号：TF777[冶金工程—钢铁冶金]