提高e级钢车钩材料强韧性研究-材料学专业论文.docx

中文摘要摘要：随着货车载重量的持续增加和运行速度的不断提高，列车各部件承受 的载荷越来越大。车钩是连接车辆的关键部件，随着运行条件日益恶劣，钩体己 出现裂纹等失效现象，成为铁路运输安全的重大隐患。重载、提速是我国货运列 车发展的趋势，因此，研制具有较高综合性能储备的车钩材料具有重要意义。本研究对现用车钩钩尾销孔部位出现的裂纹进行了失效分析；以研制高性能 储备的车钩材料为目的，有针对性地对新研制的钢种进行了化学成分、冶炼方法 的调整和改进，并进行了热处理工艺参数的优化和拉压疲劳性能、低温冲击性能、 摩擦磨损性能的试验研究。研究结果表明：裂纹起源于牵引弧面上一点，萌生后沿径向基本为脆性断裂， 扩展到淬硬层和基体的过渡区后转向周向和轴向扩展，基本为疲劳断裂。经过化 学成分调整和冶炼方法改进，新型E级钢ZG29MnMoNi—E级钢的常规力学性能符 合TB／T2942．1999和北美铁道协会AAR．M211的标准要求，并高于调研的两个铁 路工厂现用车钩材料的性能的平均水平；新钢种的拉压疲劳强度为342MPa，比现 用钢种高9．26％；新钢种与40Cr配副，对磨1h的质量磨损量为0．01 1 59，比现用钢种低90％；新钢种在一40℃时的低温冲击功集中在60．80J，是现用钢种的2～3倍。可见，新型E级钢对我国重载列车关键零部件的材料更新具有重要的工程应用参考价值，有广阔的应用前景。关键词：车钩；失效分析；拉压疲劳；低温冲击；磨损 分类号：TB 31j匕立交通太堂亟±堂僮i金塞 一 △曼墨!＆△￡!ABSTRACTABSTRACT：With the continuous increasing of wagon load and running speed，all parts of freight cars have been received more loading weight．The coupler is the key part for linking locomotive and rolling stock，but coupler body has been detected failure phenomenon such as crack with the abominable running condition，which has been serious incipient fault of railway transport．Heavy load and increasing speed is the trend in our country’S wagon development，SO it is significant to develop high comprehensive properties reserved material for coupler．Failure analysis has been done in current couplers winl cracks in coupler yoke key； aimed at high comprehensive properties reserved material，The chemical constitution has been adjusted and smelting method has been improved for the new steel，it’S heat—treatment processing parameters has also been optimized，it’S repeated tension andcompression behavior,low-temperature impact behavior and frictional behavior are alsohas been tested．The results showed that the surface cracks of coupler yoke start from some spots of traction arC surface,and expanding forwards along radial direction in a brittle fracture way．When arrivd the intermediate zone between basal body and hardening zone,the crack turned to axial and circumferential direction and expanding in fatigue way．After chemical constituti