Cr12MoV钢盐浴渗钒后的组织及耐蚀性能

Microstructure and Corrosion Resistance of Crl2MoV Steel after Salt- Bath Vanadizing

目前，对Cr12MoV盐浴渗钒层的耐蚀性鲜有研究。采用自配的混合盐对Cr12MoV钢在不同温度和时间进行盐浴渗钒处理。通过表面显微硬度测试、金相显微和SEM形貌观察、EDS和XRD分析表征了Cr12MoV渗层性能与组织结构，选定了较佳渗钒的温度（1000℃）和时间（6h），对最优工艺渗件在3．5％NaCl溶液中进行了电化学测试，以检验渗层的耐蚀性。结果表明：Cr12MoV钢渗钒后形成了致密的渗层，表面硬度从渗钒前的713HV3。提高到1800～2700HV3N；渗层厚度分别与渗钒温度和保温时间成正比关系；最优工艺渗钒后的耐蚀性比渗钒前提高了36％。

A mixed salt formulated at our laboratory was adopted to conduct salt-bath vanadizing of Crl2 MoV steel under different temperatures and for different durations.The morphology of resultant vanadizing coating on the steel surface was observed with a metallographic microscope and a scanning electron microscope,while its composition and phase structure were analyzed with an energy dispersive spectrometer and an X-ray diffractometer,respectively.Moreover,the microhardness of the vanadizing coating was determined.The optimal condition for vanadizing was established,and the corrosion resistance of the vanadizing coating obtained under the optimal vanadizing condition in 3.5%NaCl solution was evaluated by electrochemical tests.Results indicated that the optimal vanadizing temperature and time were 1000℃ and 6 h,respectively.Resultant vanadizing coating was compact,and its microhardness increased from713 HV_(3N) before vanadizing to 1800~2700 HV_(3N).Its corrosion resistance was significantly improved as compared with the untreated steel substrate.