超高碳钢的压焊顶锻行为的模拟研究摘要本文介绍了超高碳钢(UHCS) 的发展及国内外研究现状，对其应用领域进行了展望。顶锻是决定钢轨闪光焊及气压焊接头质量的关键工序。本实验采用Gleeble-1500D热模拟实验装置, 对超高碳钢加压顶锻行为进行研究,此技术用电阻加热方式进行焊接模拟, 其高能量密度热源低热量输入的快速焊接方法具有极强的热应力应变模拟功能，而且不需要焊材，不开坡口，避免了选取焊材难与母材性能匹配的问题。通过实验，确定了主要工艺参数的最佳组合。测定了焊接接头的硬度、抗拉强度，并利用图像分析仪分析了焊缝及其热影响区的微观组织。研究结果表明，最佳工艺参数组合是：加热峰值温度pT 为 1100 ℃，加热速度250 ℃ /s, 顶锻量为8cm，顶锻速度为3cm/s 。焊后其焊缝硬度可达到 HV254.3左右，接头硬度不低于母材，焊接热影响区（HAZ）未出现软化。焊后拉伸强度达到184.349MPa 。焊缝热影响区的组织为珠光体+铁素体，其中珠光体为呈超细均匀分布的，硬度高于母材，铁素体部分呈针状分布。关键词： 超高碳钢，顶锻压焊, 顶锻变形，热模拟Simulation Study of the Upending Pressure Welding on Ultra- High Carbon Steel ABSTRACT This article introduces the actualities of development and research of ultra-high carbon steel(UHCS),and forecastsits application areas .The upendingis key working procedure for the rail joints quality of flash welding and air pressure welding. In this paper, the behavior of upending pressurewelding for UHCSwas studied by using Gleeble-1500D thermal simulation equipmennt,in thisprocess the upending pressurewelding was simulated through resistance heating, the speediness welding method that is high energy densityheater and low quantity of heat feedpossesses very strong heat stress- strain simulation function.,and that,it is no need welding material no cutting slope, avoiding the matching difficultybetween welding material and base materia.The best combination of main technics parameters were confirmed by test.thehardness and tensile strength of joints were determined,...
