热轧带钢层流冷却的离散化边部遮蔽策略研究  

Strategy of discrete edge masking in the laminar cooling process of hot rolling strip

作　　者：余伟[1] 王乙法 李明辉[1] 轩康乐 

机构地区：[1]北京科技大学冶金工程研究院,北京100083

出　　处：《哈尔滨工业大学学报》2016年第11期147-154,共8页Journal of Harbin Institute of Technology

基　　金："十一五"国家科技支撑计划资助项目(2006BAE03A06)

摘　　要：层流冷却会导致高强度热轧带钢板形缺陷,合理的边部遮蔽策略有助于冷却后板形改善.针对卷取温度为500℃的12 mm厚度X70管线钢热轧带钢,建立层流冷却过程的热-力-相变耦合有限元模型,对比模拟了在常规层流冷却和离散化边部遮蔽策略下冷却过程中带钢宽度上的温度场、相变和内应力分布.结果表明:在常规层流冷却过程中,带钢边部25 mm范围内会产生塑性变形,水冷后半段的前期带钢板形有边浪的趋势,后期板形有转向中浪的趋势;而层流冷却采用离散化边部遮蔽策略时,带钢宽度方向上温差显著减小,使得贝氏体转变量和残余应力沿宽度方向上分布更均匀.这种遮蔽策略有效消除了带钢边部的塑性变形,改善了冷却板形.The laminar cooling process can cause flatness defects of high strength hot rolled strip. Proper edge masking strategy is benefit to improve its flatness after cooling. For 12 mm thickness hot rolled X70 pipeline steel strip with the coiling temperatures of 500 ℃,a coupled thermo-mechanical-phase transition model of Finite Element Model（ FEM） was established for the strip in laminar cooling process. The temperature field,phase transformation and internal stress distribution along the width of hot rolled strip were calculated in the duration of the conventional laminar cooling and the cooling process with discrete edge masking strategies. The results show that there is plastic deformation at the strip edge of 25 mm width during the conventional laminar cooling. Strip flatness tends to edge waves in the early stage and shifts to center waves in the end stage of the later half water cooling process. However,by cooling with the strategy of discrete edge masking,the temperature difference decreased significantly between edge and middle of strip in width direction,leading to evenly distributed bainite transformation and residual stress along the strip width. The masking strategies effectively eliminate the plastic deformation and improve of the flatness of the cooled strip.

关 键 词：热轧带钢 层流冷却 离散化 边部遮蔽 有限元 

分 类 号：TG335.11[金属学及工艺—金属压力加工]