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以45钢和42CrMo钢为材料,对比研究了合金元素对离子碳氮共渗化合物层生长动力学的影响。利用光学显微镜、显微硬度计和X射线衍射仪对化合物层的显微组织、厚度、硬度及物相进行了测试和分析。结果表明,相同工艺条件下,42CrMo钢表面形成的化合物层厚度比45钢薄,但有效硬化层较厚,表面硬度高且截面硬度梯度较为平缓;随着保温时间的延长,45钢离子碳氮共渗后化合物层中的主要物相发生了γ’-Fe4(C,N)→ε-Fe2-3(C,N)的转变,而在42CrMo钢表层则无该转变,但出现了CrN、CrC及Mo2(C,N)相;动力学分析表明42CrMo钢形成化合物层的扩散激活能为66.95kJ/mol,接近45钢27.89kJ/mol的2.5倍,同时分析了合金元素对活性C、N原子扩散的影响机理。
Using 45 steel and 42CrMo steel as materials, the effects of alloying elements on the growth kinetics of ionic carbonitriding compounds were studied. The microstructure, thickness, hardness and phase of the compound layer were tested and analyzed by optical microscope, microhardness tester and X-ray diffractometer. The results show that under the same process conditions, the thickness of the compound layer formed on the surface of 42CrMo steel is thinner than that of 45 steel, but the effective hardened layer is thicker, the surface hardness is higher and the hardness gradient of section is relatively gentle. With the increase of holding time, The transformation of γ’-Fe4 (C, N) → ε-Fe2-3 (C, N) took place in the main phase of the compound layer after co-infiltration, but not in 42CrMo steel. However, CrC and Mo2 (C, N) phases. The kinetic analysis shows that the diffusion activation energy of the 42CrMo steel compound layer is 66.95kJ / mol, which is close to 2.5 times of 27.89kJ / mol of 45 steel. The effects of alloying elements on the activity of C, N The Mechanism of Atomic Diffusion.