75N U95Cr重载用过共析钢轨气压焊质量研究

75N U95Cr重载用过共析钢轨气压焊质量研究 Research on gas pressure welding quality of 75N U95Cr hypereutectoid rail for heavy haul railways 廖马宏 LIAO Mahong 1 first-author 戴虹 DAI Hong 1 corresp 2236541791@qq.com 杨翰 YANG Han 1 郑霄 ZHENG Xiao 1 西南交通大学材料科学与工程学院 西南交通大学材料科学与工程学院 School of Material Science and Engineering, Southwest Jiaotong University School of Material Science and Engineering, Southwest Jiaotong University 在大秦、朔黄等重载铁路线路上,为了更好地满足钢轨高耐磨性的使用需求,攀钢集团研发出了1 330 MPa高耐磨U95Cr过共析钢轨,现场焊轨施工亟需可靠稳定高效的焊接工艺。采用GPW-1200数控式气压焊轨机对75N U95Cr钢轨开展了焊接和正火工艺试验研究。结果表明,采用该套工艺参数焊接(第一阶段,乙炔/氧气:111/107 SLM,焊接加热270 s;第二阶段,乙炔/氧气:92/87 SLM,焊接加热90 s)U95Cr接头,硬度满足《试铺试验用高耐磨、高强韧过共析钢轨气压焊接技术条件》要求,落锤、静弯、疲劳、拉伸、冲击、金相及晶粒度满足TB/T 1632.4 《气压焊接》要求,气压焊接头性能稳定性、可靠性好,与闪光焊接头性能相当。 In order to better meet the requirements of rails with high wear resistance on heavy haul railways such as Daqin and Shuohuang, Panzhihua Iron and Steel Group has developed 1330 MPa high-wear-resistant U95Cr hypereutectoid rails.Reliable, stable and efficient welding technology is urgently needed in site rail welding construction. In this paper,experimental studies on welding and normalizing process of 75N U95Cr rails were carried out by the GPW-1200 digital control gas pressure welding machine. The results show that the hardness of U95Cr welded joints with this set of process parameters（The first stage: Acetylene/oxygen 111/107 SLM, welding heating for 270 s; the second stage: Acetylene/oxygen 92/87 SLM, welding heating for 90 s） meets the requirements of "Technical Conditions for Gas Pressure Welding of High-Wear-Resistance, High-Strength-Toughness Hypereutectoid Rails for Trial Laying Tests",and the drop weight, static bending, fatigue, tensile, impact,metallographic and grain size meet the requirements of TB/T1632.4 "Gas Pressure Welding". The performance of the gas pressure welding joints is stable and reliable, which is equivalent to the performance of the flash welding joints. U95Cr过共析钢轨 气压焊 正火工艺试验 力学性能 U95Cr hypereutectoid rail gas pressure welding normaliziong process test mechanical property U213.92 国家重点研发计划（2017YFB4501） 2022-03-08 9 51