Al-Cr急冷合金薄带与不锈钢接触反应行为分析

Analysis on behaviors of contact reaction between quenched Al-Cr foils and stainless steel

摘要: 用急冷Al-Cr合金薄带在201奥氏体不锈钢表面制备含Al,Cr元素的涂层.用光学显微镜(OM),扫描电镜(SEM),能谱分析(EDS)对界面进行了微观分析,用X射线衍射分析(XRD)、差热分析法(DTA)对薄带的组织结构及相转变进行了检测.同时还对反应机理进行了讨论.结果表明,720℃温度下,Cr元素含量高于8%(质量分数)的急冷Al-Cr合金薄带中含有Al₄₅Cr₇析出相,阻止了与不锈钢基体接触反应的进行;而8%Cr及以下的薄带可与基体发生反应,形成冶金结合.表面合金层由表及里依次为含Cr,Ni,Mn元素的FeAl₃,Fe₂Al₅,FeAl等组织.

Abstract: The Al-Cr alloy coating on 201 austenitic stainless steel surfaces was prepared by quenched Al-Cr foils. The interface microscopic analysis was carried out by OM, SEM and EDS. The structures and phase changes of quenched Al-Cr foils were analyzed by XRD and DTA. The results showed that the quenched Al-Cr alloy foils which were more than 8% of Cr contained precipitated phase Al₄₅Cr₇ at 720℃ that prevented the foils contact reaction with the stainless steel substrate. The foils which are less than 8% Cr could react with the substrate, and formed metallurgical bonding. The Al-Cr alloy coating was composed of Cr, Ni, Mn contained FeAl₃, Fe₂Al₅, FeAl and so on from outside to the inside. The reaction mechanism was also discussed.