碳化物及合金元素对酸液膜中晶粒腐蚀形态的影响

选用10#钢、65#钢和W6Mo5Cr4V2Al钢为实验材料,利用光学显微镜、扫描电镜和电子探针对其在酸性环境中腐蚀后的晶粒微观形貌和合金元素的分布进行观察分析,考察合金元素和碳化物的存在形式对晶粒腐蚀形态的影响.结果表明,晶粒的腐蚀形貌与碳化物分布有关,钢中碳元素以固溶形式存在或钢中添加Cr,Al元素,可显著提高钢的耐酸蚀性;在以电化学腐蚀为主的酸性环境中,组织中各相电极电位的高低才是晶粒是否易被腐蚀的本质;晶界是否易被腐蚀也主要与晶界处物相的电极电位高低有关.

Effect of Carbides and Alloy Elements on Grain Corrosion Morphology in Acid Liquid Film

Taking the steels ^#10， ^#65 and W6Mo5Cr4V2Al as experimental materials， the grain microstructure and alloying element distribution after corrosion treatment in acid environment were observed and analyzed by optical microscope， scanning electron microscope and electron probe. The effects of existing forms of carbides and alloying elements on the grain corrosion morphology in these steels were also studied. The results show that the corrosion morphology of grains is related to distribution of carbides in steel and that C in the form of solid solution and Cr， Al added in steel can significantly improve the corrosion resistance of the steel. In acid environment with electrochemical corrosion， the electrode potential level of each phase in microstructure is the essence that determines whether or not the grains are liable to be corroded， while grain boundary is apt to be corroded or not is also mainly related to the electrode potential level of phases at grain boundary.