高速电弧喷涂FeMnCrAl/Cr3 C2涂层热腐蚀行为

用高速电弧喷涂技术和自行研发的FeMnCrAl/Cr3C2粉芯丝材,在20钢样品表面制备了FeMnCrAl/Cr3C2涂层,采用光学显微镜、场发射扫描电镜、能谱分析和X射线衍射等方法,对FeMnCrAl/Cr3C2涂层的显微组织和热腐蚀行为进行了研究,并与20钢做了对比试验研究.结果表明:FeMnCrAl/Cr3C2涂层主要由固溶相的凝片叠加组成,中间夹杂着氧化物相、未熔颗粒相和孔隙;FeMnCrAl/Cr3C2涂层抗热腐蚀性能明显优于20钢基体,热腐蚀增重约为20钢的1/3-1/4,涂层抗腐蚀性能提高的原因主要是:涂层热腐蚀后表面生成具有保护性的、致密的含Al、Cr氧化物和Cr与Fe的复合氧化物,阻碍了涂层进一步腐蚀.

Hot corrosion performance of FeMnCrAl/Cr3C2 coatings deposited by high velocity arc spraying

FeMnCrAl/Cr3C2 coating was deposited on AISI 1020 steel substrate using a type of self-developed FeMnCrAl/Cr3 C2 alloy cored wire by high velocity arc spraying.Microstructure and hot corrosion performance of FeMnCrAl/Cr3C2 coating at 700℃ were studied and analyzed by field emission scanning electron microscopy (FE-SEM),energy dispersion spectrum (EDS) and X-ray diffraction (XRD) analysis.The results showed that FeMnCrAl/Cr3C2 coating was structurally featured by consisting of slatted layers of mainly Fe solid solution phases mixed with oxide phases,un-melted particles and pores.The hot corrosion resistance of FeMnCrAl/Cr3 C2 was obviously improved that of AISI 1020 steel substrates.The improvement was basically attributed to the formation of aluminum oxide,chromium oxide and spinels of chromium and iron on the coating surface.These oxides blocked further corrosion,and hindered the corroding and oxidizing inward progress.