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本文对经过600℃×6小时软氮化的20钢及35钢试样再进行650°—900℃不同温度加热急冷处理,然后分别对各试样进行金相、电子金相等物理检验和各种力学性能试验。其结果表明,经过软氮化后的钢件再在650℃加热30分钟时,铁的氮化物(ε·Υ′)开始分解,在750℃加热15分钟氮化物分解完毕,同时N原子向深层扩散,淬火后可获得一定厚度C—N马氏体层,进而提高了各项力学性能指标。检验发现再加热时ε相先在其和α及Υ相相界面上分解,然后在ε相相同界面分解,析出的氮原子向深层扩散。试验确定了软氮化后再加热时渗层组织变化和温度及加热时间的关系。
In this paper, the specimens of 20 and 35 steel nitrocarburized at 600 ℃ for 6 hours were further heated and quenched at different temperatures of 650 ° -900 ° C. Then, the specimens were examined metallographically and electronically, respectively, Mechanical properties of the test. The results show that when the nitrocarburized steel is further heated at 650 ° C for 30 minutes, the iron nitride (ε · Y ’) starts to decompose and the nitride is decomposed by heating at 750 ° C for 15 minutes, while the N atom is deep into the deep layer Diffusion, quenched to obtain a certain thickness of C-N martensite layer, thereby enhancing the various mechanical properties. It is found that when reheating, εphase firstly decomposes at the interface ofαandγ, and then decomposes at the same interface of εphase, and the precipitated nitrogen atoms diffuse to deeper layers. The relationship between the microstructure and the temperature and the heating time of the nitrided layer after the nitrocarburizing was confirmed by experiments.