42CrMo钢锌铝共渗层的组织及性能

Microstructure and properties of Zn-Al thermochemical treated on 42CrMo steel

研究了42Cr Mo钢在不同锌铝共渗温度、共渗时间条件下共渗层的组织及性能。用金相显微镜、扫描电镜观察了锌铝共渗层的形貌及厚度;用X射线衍射仪分析了共渗层的物相组成;对比了纯锌渗层与共渗层耐蚀性。结果表明:在400℃下保温不同时间,渗层的厚度随时间的增长而逐渐增加;在不同温度下保温3 h时,渗层的厚度随温度的升高而逐渐增大;锌铝共渗的试样比单纯渗锌试样的耐腐蚀性能好,渗锌件出红锈时间为50 h,渗锌铝件为127 h,有效延长了耐盐雾腐蚀时间。

The microstructure and properties of Zn-Al thermochemical treated layer on 42 Cr Mo steel were studied. The cross-section morphology of the Zn-Al alloyed layer was observed by means of optical microscope and scanning electron microscope,and the thickness of ZnAl thermochemical treated layer was tested by microscope. The phase structure of Zn-Al thermochemical treated layer was analyzed by means of X-ray diffraction. The comparison of the corrosion resistance between the Zn-Al thermochemical treated sample and the zincized sample was conducted in Na Cl neutral salt spray environment. The results show that,when the temperature is 400 ℃,the thickness and hardness of Zn-Al thermochemical treated layer gradually increase with time. When the time is 5 h,the thickness of the Zn-Al thermochemical treated layer increases with temperature. The corrosion resistance of the sample after the Zn-Al thermochemical treated is better than that of the zincized sample treatment. The time of appearing red rust to the zincized layer is 50 h. The time of appearing red rust to the Zn-Al thermochemical treated layer is 127 h. The corrosion resistance of Zn-Al thermochemical treated 42 Cr Mo steel can be extended effectively.