U71Mn钢轨压焊顶锻行为模拟研究

Investigation in Thermal and Mechanical Simulation of Upset Deformation on U71Mn Rail Butt Welding

顶锻是决定钢轨闪光焊及气压焊接头质量的关键工序。本文采用Gleeble热模拟试验技术,对U 71Mn钢轨加压顶锻行为进行研究,为无缝线路焊轨工程的工艺选择和质量控制提供数据。结果表明:钢轨焊接所需顶锻力随顶锻量、顶锻速度的增加而增大,随焊口温度的降低而升高。匹配好顶锻力、顶锻速度、顶锻量等参数,促使焊口金属充分进行交互结晶和形变再结晶,可获得优质的焊接接头。通过观察焊瘤是否具有均匀分布的毛刺特征,可以初步判断顶锻参数的匹配效果。

The upset process of flash welding ＆ gas pressure welding decides the quality of rail weld joints. In this paper, the advanced American Gleeble simulation is used to explore the thermal and mechanical simulation experiment of rail steel（U 71Mn）butt welding in the process of upset formation, which provides data for technique selection and quality control in CWR welding eugineering. The results show that the upset force increases with the increasing of the upset length and upset speed, and increases with the reducing of the heating temperature. Good match among the parameters of the upset length, upset speed and upset force helps to promote sufficient alternate crystalizing and deformed re-crystalizing in the weld metal, and create good-quality weld joints. The matching effect can be observed by the fact whether the burr distribution is uniform or not.