摘要
由于钢轨闪光对焊后接头存在晶粒粗大等问题,无法满足性能要求,因此必须进行焊后热处理。常见焊后热处理一般分为两部分,即感应加热与喷风冷却,喷风冷却会通过冷速影响接头组织,在焊后热处理中占据重要地位。为了探究该过程,本文基于流体仿真软件FLUENT对U75V钢轨焊后热处理的喷风冷却过程进行数值模拟。仿真结果表明,正火喷风冷却时,轨腰与轨头的交界处上端出现最低流场流速,冷却速度较低,轨底两侧的流场流速最高,冷却速度最快。正火喷风冷却时的温度场具有以下分布特点。一是轨头与轨底中心温度高,轨腰温度低,三者的散热能力从高到低依次是轨底、轨腰、轨头;二是在喷风盒不同位置处采用不同喷风压力,采用降低轨腰与轨底的喷风压力、增加轨头的喷风压力的方法能够获得较好的冷却效果。
Due to the presence of coarse grains and other issues in the joint after flash butt welding of rails,it does not meet the performance requirements and therefore must undergo post-weld heat treatment.Common post-weld heat treatment is generally divided into two parts:induction heating and spray cooling.Spray cooling affects the joint structure through the cooling rate and plays a significant role in post-weld heat treatment.In order to explore this process,this paper conducts a numerical simulation of the spray cooling process in the post-weld heat treatment of U75V rail steel based on the fluid simulation software FLUENT.The simulation results indicate that during the normalizing spray cooling,the lowest flow velocity and slowest cooling rate occur at the upper part of the junction between the rail web and the rail head,while the highest flow velocity and fastest cooling rate are found on both sides at the rail bottom.The temperature field during the normalizing spray cooling has the following distribution characteristics:the center of the rail head and rail bottom have higher temperatures,while the rail web has a lower temperature.The heat dissipation capacity of the three,from high to low,is in the order of rail bottom,rail web,and rail head;using different spray cooling pressures at different positions of the cooling box,and employing a method that reduces the spray pressure at the rail web and rail bottom while increasing the spray pressure at the rail head can achieve better cooling effects.
作者
高林
GAO Lin(China Railway First Group Xinyun Engineering Co.,Ltd.,Xianyang Shaanxi 712000)
出处
《中国科技纵横》
2024年第15期92-96,共5页
China Science & Technology Overview
关键词
U75V钢轨
喷风冷却
工艺参数优化
温度场
数值模拟
U75V rail
spray cooling
process parameter optimization
temperature field
numerical simulation
