【作者】 李建华；

【导师】 潘一凡；

【作者基本信息】 南京林业大学 ， 机械设计及理论， 2003， 硕士

【摘要】 改革开放以来，我国从先进发达国家引进了很多汽车生产技术，使我国的汽车生产和质量水平上了一个很大的台阶。引进技术的最终目的是实现国产化，其中汽车传动系统(变速箱和后桥)齿轮材料国产化及热处理工艺研究是最重要的工作之一。 本文根据引进汽车齿轮钢的技术条件，委托大冶钢厂冶炼了20MnCr5钢，对钢材的成分、力学性能、淬透性、晶粒度、纯净度、低倍组织等项目进行了检验。并对检验内容、检验方法及检验结果等作了详细的介绍，复检结果表明大冶钢厂冶炼的20MnCr5钢符合引进产品的技术条件要求，为后续工作打下了良好的基础。 在此基础上，进行了一系列的预备热处理工艺试验，找出了最佳的预备热处理工艺方案，从而改善了齿轮毛坯的切削加工性能，使其组织、性能更加均匀稳定，减少了热处理变形；还进行了渗碳热处理工艺试验，并采用碳势自动控制技术，使齿轮的热处理质量达到引进产品的技术条件要求；分析了影响热处理变形的各种因素，摸索出控制热处理变形的有效措施。 本文还就真空脱气钢和普通电炉钢进行了接触疲劳和弯曲疲劳试验，系统地研究了纯净度对齿轮钢疲劳性能的影响。更多还原

【Abstract】 China has imported many-advanced foreign technology of manufacturing automobile since reform and opening to the world. It greatly improved the technology and quality of our automobile. But our last goal is to manufacture automobiles using our own technology. For this, one of the important things is to research the gear steel of the automobile and it heat treatment technology.So according to the requirement of the import product, we entrusted Da Ye iron and steel works to smelt the gear steel-20MnCr5. After this we test the chemical composition, mechanical property, quenches hardenbility, grain-size, impurities and low multiple microstructures etc of the steel made by Da Ye iron and steel works, and also drifted the contents, method and the result of the test in detail. The test result show that the steel of 20MnCr5 made by Da Ye tally with the requirement of the import automobile technology.On this base, we conducted a series of heat treatment such as conditioning heat treatment and carburizing, and found out an optimum technology parameter of heat treatment. Thereby improved the machinability of gear blank and made it’ s structure more even and stable and at the same time reduced the deformation of heat treatment. This paper also analyzed the influence factor of deformation of heat treatment and come to a conclusion of controlling the deformation according to the test result and analyses.At the same time, we also conducted the test of the contact fatigue and the bending fatigue of the material and studied system on the influence of the purity on the fatigue property of the gear steel.更多还原