高速电弧喷涂FeNiCrTiB/Cr_3C_2涂层的组织结构及其高温氧化行为

Microstructure and High Temperature Oxidation Resistance of FeNiCrTiB/Cr_3C_2 Coating Deposited by High Velocity Arc Spray

采用高速电弧喷涂技术制备FeNiCrTiB/Cr3C2耐高温金属陶瓷复合涂层。利用光学显微镜、扫描电镜、X射线衍射等手段研究涂层的组织结构以及氧化产物,并与传统锅炉用钢20G钢对比,分析涂层的抗氧化机理。结果表明:FeNiCrTiB/Cr3C2涂层为典型的层状结构,且涂层上分布着少量的孔隙和氧化物;650℃氧化200h后涂层的氧化质量增量为1.58mg·cm-2,远小于20G钢的氧化质量增量(24.85mg·cm-2);涂层在氧化过程中生成致密的具有保护性的铁、铬的复合氧化膜,阻塞氧的扩散通道,阻止进一步氧化,从而提高涂层的抗高温氧化性能。

The metal-ceramic composite coating FeNiCrTiB/Cr3C2 with high temperature corrosion resistance was prepared by high velocity arc spray(HVAS).The optical microscopy,scanning electron microscopy and X-ray diffraction were used to analyze microstructure and oxidation products of the coating.The high temperature oxidation resistance of FeNiCrTiB/Cr3C2 coating was compared with that of bare 20G steel.The high temperature oxidation mechanism of the coating was investigated.The results showed that microstructure of HVAS FeNiCrTiB/Cr3C2 coating was the typical layer structure.Some pores and oxides were distributed on coating.After oxidation in 650℃ for 200h,the weight gain of the FeNiCrTiB/Cr3C2 coating was 1.58mg·cm-2,which was much less than that of the bare 20G steel(24.85 mg·cm-2).The formation of the compact Fe,Cr composite oxides was responsible for the protection of the coating from further oxidation.