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选择合适的介质成分,45钢盐浴及电解渗硼均可得到单相的Fe_2B渗层。本文通过对700—900℃各温度渗硼结果的综合比较发现:45钢(α+r)两相区温度是低温渗硼的最佳温度。实验发现,介质中加入一定量的稀土,可显著地增加各工艺相同温度下的渗层厚度,在一定程度上弥补了低温时由于原子扩散能力较低而造成的渗层厚度的损失,使低温渗硼工艺更加可行。同时也发现,稀土可渗入到Fe_2B中,并且由于稀土的渗入,使渗层组织得到改善,韧性、耐蚀性及耐磨性得到提高。 应用扫描电子显微镜、电子探针、电子能谱、正电子湮没、x射线衍射、显微硬度计等设备,对渗硼后钢表面的缺陷、成分、相的分布进行了全面的考察和测定。在此基础上对稀土的促渗、改善组织、提高性能的机理,进行了初步的探讨。
Select the appropriate medium composition, 45 steel salt bath and electrolytic boron can be single phase Fe 2 B layer. In this paper, a comprehensive comparison of the results of boronizing at temperatures of 700-900 ℃ found that the temperature of 45-phase (α + r) zone is the optimum temperature for boronizing at low temperature. It is found that adding a certain amount of rare earth into the medium can significantly increase the thickness of the diffusion layer at the same temperature for each process and to some extent compensate for the loss of the thickness of the diffusion layer due to the low atomic diffusion capacity at a low temperature, Boronizing process is more feasible. Also found that rare earth can penetrate into the Fe_2B, and due to the infiltration of rare earth, so that the infiltration layer organization has been improved, toughness, corrosion resistance and wear resistance is improved. The defects, composition and phase distribution of the steel after boronizing were comprehensively investigated and determined by using scanning electron microscopy, electron probe, electron spectroscopy, positron annihilation, x-ray diffraction and microhardness tester. On this basis, the rare earths to promote seepage, improve the organization, improve the mechanism of performance, conducted a preliminary discussion.