直流电场对42CrMo钢盐浴渗氮催渗与改性作用

发布时间：2019-05-18 01:21

【摘要】：以42CrMo钢为材料,对比研究了传统和直流电场催渗盐浴渗氮技术。利用光学显微镜、显微硬度计和X射线衍射仪对渗层的显微组织、渗层厚度、硬度及物相进行了测试和分析。研究结果表明:直流电场可以显著提高盐浴渗氮速度,降低渗氮温度或缩短渗氮时间;在外加电压7.5 V直流电场条件下,保温时间为80 min时,处理温度530℃获得的化合物层厚度与同样时间常规盐浴渗氮560℃时获得的层深相近,约为6.7μm,处理温度为560℃时化合物层厚度提高到12.1μm。虽然直流电场不改变42CrMo钢盐浴渗氮层的主要物相,均由ε-Fe_3N相、γ'-Fe_4N相和Cr N相构成,但直流电场盐浴渗氮后渗层中硬度较高的γ'-Fe_4N相的相对含量更高。因此,直流电场盐浴渗氮处理后的42CrMo钢的截面显微硬度大幅度的提高,经过575℃×80 min,7.5 V盐浴渗氮后的试样截面显微硬度达到1100 HV0.01,是基体硬度的3倍。同时,施加电场盐浴渗氮使42CrMo钢耐蚀性比常规盐浴渗氮进一步提高。
[Abstract]:Using 42CrMo steel as material, the traditional and DC electric field catalytic salt bath nitriding technology was compared and studied. The microstructure, thickness, hardness and phase of the infiltrated layer were measured and analyzed by optical microscope, microhardness tester and X-ray diffractometer. The results show that DC electric field can significantly increase the nitriding speed of salt bath, reduce the nitriding temperature or shorten the nitriding time. Under the condition of applied voltage 7.5V DC electric field and holding time of 80 min, the thickness of compound layer obtained at 530C is similar to that obtained at 560C in conventional salt bath nitriding at the same time, which is about 6.7 渭 m. When the treatment temperature is 560 鈩，

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