45钢热处理空冷过程分析.doc

45钢热处理空冷过程分析 摘要：45钢是一种十分常见及用量非常高的金属材料，硬度较低，强度较高，塑性和韧性好，切削加工性能较好，综合机械性能比较好。通过适当的热处理以后可改变钢的内部组织结构，具有一定塑性、韧性和耐磨性。45钢常用来做用于制作承受负荷较大的小截面调质件和应力较小的大型正火零件，以及对心部强度要求不高的表面淬火零件，如曲轴、传动轴、齿轮、蜗杆、键、销等。 通过ANSYS有限元分析软件来模拟45钢热处理空冷过程中温度场随时间的变化关系，ANSYS结合了材料变温过程材料热物性参数的变化，特别适合钢件正火过程温度场的准确计算。模拟得到试件温度随正火时间的分布关系图。对45钢圆柱试样、冲击试样、拉伸试样进行热处理完成金相组织观察、拉伸试验、硬度测试试验，记录数据并比较结果；比较45钢热处理前后组织及力学性能的变化和与45钢水淬后的组织和力学性能的比较，通过实验结果表明：正火由于冷却速度稍快，与退火组织相比，组织中珠光体量相对比较多，而且片层较细密，细化了晶粒，使碳化物分布均匀化，所以组织和性能有所改善，同时消除了材料残余应力。对低碳钢来说，正火后提高硬度可改善切削加工性，提高零件表面光洁度。 45 steel heat treatment process of air cooling analysis Abstract：45 steel is a very common and very high amount of metal materials, low hardness, high strength, good ductility and toughness, better cutting performance, better mechanical properties. After an appropriate heat treatment by changing the internal organizational structure of steel, has a certain plasticity, toughness and wear resistance. 45 for the production of steel commonly used to bear a greater load quenched small section of the large pieces of normalizing and stress smaller parts, as well as the strength of the core part of the surface hardening less demanding parts such as crankshafts, drive shafts, gears, worm , keys, pins, etc. By ANSYS finite element analysis software to simulate the process of air-cooled heat treated steel 45 with variation of temperature field time, ANSYS combination of process variable temperature change material thermal parameters of materials, especially for steel normalizing process to accurately calculate the temperature field. Simulated specimen temperature distribution over time normalizing relationship diagram. 45 steel cylindrical specimens, impact specimens, tensile specimens subjected to heat treatment to complete the microstructure observation,tensile test, hardness test trials, the recorded data and compare the results; 45 before and after heat treatment of steel microstructure and mechanical properties of changes in microstructure and mechanical properties and comp