摘要：本论文介绍了20Cr渗碳钢样品加热工艺对淬火组织的影响。在淬火前和淬火后渗碳样品表层组织、过渡组织和心部组织的变化进行研究和对比，以及通过淬火后样品的硬度测定，找到淬火加热温度对样品组织和力学性能的影响情况。得出结论，经过淬火后，试样表层没有珠光体存在，同时770℃和800℃心部有铁素体，830℃和860℃心部没有铁素体。所以830℃和860℃相对硬度也有一定的提高。淬火后伴随着组织的变化，其样品的硬度有了很大的提升。样品的表层梯度硬度变化规律出现了先增加而后降低。总体来说，样品硬度从表层到渗碳边缘硬度呈现递减状态。32478
毕业论文关键词： 渗碳钢；20Cr；淬火
Study on the microstructure of 20Cr steel carburizing samples
Abstract: The effect of heating process of 20Cr carburizing carbon steel on the microstructure of quenching is introduced in this paper.. In before quenching and quenching after carburizing sample surface microstructure, transition and changes were research and comparison, and through the determination of the hardness of the quenched samples, find quenching heating temperature on Microstructure and mechanical properties of samples. It was concluded that there was no pearlite in the surface of the sample after quenching, and there was no ferrite at the same time at 770 and 800 for the heart and there was no ferrite at 830 and 860.. So the relative hardness of 830 and 860 can also be improved.. After the quenching, the hardness of the samples has been greatly improved with the change of the microstructure.. The change of surface hardness of the samples increased first and then decreased.. Overall, the hardness of the sample is decreased from the surface to the edge of the carburizing.
Keywords:  carbon steel; 20Cr; quenching
目录
1 绪论    1
1.1 渗碳钢简介    1
1.1.1 渗碳钢的定义    1
1.1.2 渗碳的目的和分类    1
1.1.3 渗碳钢工件的工艺流程    2
1.1.4 渗碳钢的应用    2
1.2 热处理淬火简介    3
1.2.1热处理淬火的基本原理    3
1.2.2常用淬火介质及冷却特性    3
1.2.3钢的淬透性    3
1.2.4淬火后样品的性能特点    4
1.3渗碳钢的热处理    4
1.3.1渗碳钢的热处理    4
1.3.2渗碳后钢的组织与性能    5
1.4渗碳钢热处理发展现状和分析    5
1.5选题的目的和意义    7
2 实验方案和方法    8
2.1实验材料    8
2.1.1材料的成分    8
2.1.2加热临界温度    8
2.1.3原始试样的状态    9
2.2淬火加热热处理    9
2.2.1试验方案    9
2.2.2淬火工艺参数    9
2.2.3 20Cr渗碳钢样品热处理工艺参数的确定    10
2.2.4 20Cr渗碳钢样品热处理工艺过程    11
2.3 20Cr钢渗碳样品金相制样以及组织观察    11
2.3.1 淬火后镶嵌    11
2.3.2金相制样工艺    12
2.3.3组织观察和记录    12
2.3.4组织状态的分析    12
2.4硬度测定方法    12
2.4.1硬度种类的选择    12
2.4.2硬度的测定    15
2.4.3实验所用材料和设备    15
3 实验结果和分析    16
3.1 20Cr钢渗碳原始样品的组织和硬度分析    16
3.2 770℃下淬火后20Cr钢渗碳样品的组织和硬度分析    17 20Cr钢渗碳样品淬火组织的研究:http://www.youerw.com/cailiao/lunwen_29092.html