高速火焰喷涂FeCoCrNiAlTi高熵合金涂层的耐高温氯腐蚀性能  

High Temperature Chlorine Corrosion Resistance of FeCoCrNiAlTi High Entropy Alloy Coatings Prepared by High-velocity-oxygen-fuel Spraying

作　　者：张学斌[1,2] 胡树森 汪友路 代真 初希 王平 苏海林 ZHANG Xue-bin;HU Shu-sen;WANG You-lu;DAI Zhen;CHU Xi;WANG Ping;SU Hai-lin(School of Materials Science and Engineering,Hefei University of Technology,Hefei 230009,China;Engineering Research Center of High Performance Copper Alloy Materials and Processing,Ministry of Education,Hefei 230009,China;China Power Hua Chuang Electricity Technology Research Co.,Ltd.,Jiangsu Suzhou 215123 China;Hefei Kede Surface Technology Co.,Ltd.,Hefei 230088,China)

机构地区：[1]合肥工业大学材料科学与工程学院,合肥230009 [2]高性能铜合金材料及成形加工教育部工程研究中心,合肥230009 [3]中电华创电力技术研究有限公司,江苏苏州215123 [4]合肥科德电力表面技术有限公司,合肥230088

出　　处：《表面技术》2022年第8期381-386,共6页Surface Technology

摘　　要：目的提高垃圾焚烧发电锅炉的水冷壁和过热器管等部件的使用寿命,确定具有最佳耐高温氯腐蚀性能的高熵合金FeCoCrNiAlTix的成分。方法采用高速火焰喷涂在Q235基体上制备FeCoCrNiAlTi_(x)(x=0、0.4、0.8、1.2、1.6)高熵合金涂层,运用扫描电子显微镜、X射线衍射仪研究Ti含量对涂层形貌和组织结构的影响,并测试涂层的抗热震性能和耐高温氯腐蚀性能。结果高速火焰喷涂熵合金涂层呈典型的层状结构,随着Ti含量的增加,涂层的孔隙率降低,x=1.2时涂层的致密度最高,其孔隙率仅为0.46%。添加Ti后的高熵合金涂层由FCC相和BCC相组成,随着Ti含量的增加,FCC相逐渐减少,涂层主要为BCC相。在800℃到常温的循环热震试验中,高熵合金涂层具有良好的抗热震性能。在60 h的高温熔盐腐蚀后,所有高熵合金涂层相较Q235具有显著的耐高温氯腐蚀性能,对高温腐蚀质量变化进行拟合,发现其满足幂函数模型。结论添加适量的Ti能够改善FeCoCrNiAlTi_(x)高熵合金涂层的成形质量,降低涂层的孔隙率,其中高速火焰喷涂FeCoCrNiAlTi_(1.2)涂层的孔隙率最低,抗热震性能和耐高温氯腐蚀性能最好。The furnace wall cooling surface and super heater tube of waste incineration power generation boiler are strongly corroded by high temperature chlorine.In view of the excellent high temperature oxidation resistance of high entropy alloy,the high temperature chlorine corrosion resistance of FeCoCrNiAlTix(x=0,0.4,0.8,1.2,1.6)high entropy alloy coating was studied.In terms of the method,the FeCoCrNiAlTix high entropy alloy coating was prepared by high-velocity-oxygen-fuel spraying on the Q235 substrate,and the effect of Ti content on the morphology and structure of the coating was studied by scanning electron microscope and X-ray diffractometer,the thermal shock resistance and high temperature chlorine corrosion resistance of the coating were tested.The results show that the high entropy alloy coating presents a typical layered structure.With the increase of Ti content,the porosity of the coating decreases continously.The highest density of the coating is obtained when Ti content is FeCoCrNiAlTi_(1.2),while the porosity is only 0.46%.The high entropy alloy coating without Ti is composed of FCC phase and BCC phase;with the increase of Ti content,the FCC phase decreases gradually and the coating structure is mainly composed of BCC phase.High entropy alloy coatings have good thermal shock resistance in cyclic thermal shock tests from 800℃to room temperature.Furthermore,the high entropy alloy coatings have remarkable resistance to high temperature chlorine corrosion in high temperature molten salt environment,and the relationship between the mass change of the coatings and time is satisfied with the power function.Comprehensive analysis shows that the addition of an appropriate amount of Ti can improve the forming quality of FeCoCrNiAlTix coating and reduce the porosity of the coating.Among them,the porosity of FeCoCrNiAlTi_(1.2) coating is the lowest,and the thermal shock resistance as well as high temperature chlorine corrosion resistance are the best.

关 键 词：高熵合金涂层 FeCoCrNiAlTi 高温氯腐蚀 高速火焰喷涂 组织结构 

分 类 号：TB37[一般工业技术—材料科学与工程]