摘要
针对涂覆在GH907合金试样上NiCrSiB涂层,采用光学显微镜和拉伸试验机对热处理前后涂层组织结构形貌、拉伸结合强度进行了分析和比对,并对热处理后的涂层开展了涂盐热腐蚀、电偶腐蚀及盐雾腐蚀试验及分析研究。结果表明:大气等离子喷涂态的NiCrSiB涂层经热处理后,涂层的结合形式由颗粒堆积的层状物理结合转变为冶金结合,涂层中的孔洞等组织特征明显改善;热处理后涂层厚度在80~140μm内结合强度值相对稳定;涂层涂盐热腐蚀随着时间变化腐蚀速率逐步增大;电偶腐蚀表明涂层的电势比基体材料的电势低;涂层盐雾试验所产生的黄色流痕,主要为盐雾中Cl-与涂层中活泼Fe元素在长时间接触中所形成的FeCl_(3)和FeCl_(2)等在涂层表面微孔结构处的聚集产物。
The microstructure and tensile bond strength of NiCrSiB coating on GH907 alloy samples before and after heat treatment were analyzed and compared by optical microscope and tensile testing machine.The salt-coated hot corrosion,galvanic corrosion and salt fog corrosion of the coatings after heat treatment were analyzed and studied.The results show that the bonding form of NiCrSiB coating is changed from physical bonding of particle accumulation to metallurgical bonding after heat treatment,The microstructure characteristics such as holes in the coating are significantly improved.The tensile bond strength of the coating decreases with the increase of the thickness both before and after heat treatment.After heat treatment,the bonding strength of the coating with a thickness in the range of 80μm to 140μm is relatively stable.The salt-coated hot corrosion of coating is proportional to the corrosion time.Galvanic corrosion shows that the potential of the coating is lower than that of the base material.The yellow flow marks produced by the saltfog corrosion test of the coating are mainly the accumulation products of FeCl 3 and FeCl 2 on the microporous structure of the coating surface,which are formed by the Cl-ion in the salt spray and the active Fe element in the coating during the long-term contact.
作者
刘晓飞
王斌利
胡江波
王建锋
李卫军
刘建明
LIU Xiaofei;WANG Binli;HU Jiangbo;WANG Jianfeng;LI Weijun;LIU Jianming(AECC Aviation Power Co.,Ltd.,Xi′an 710021,China;BGRIMM Advanced Material Science&Technology Co.,Ltd.,Beijing 102206,China)
出处
《热喷涂技术》
2024年第3期106-112,共7页
Thermal Spray Technology
关键词
大气等离子喷涂
NiCrSiB合金
防腐涂层
盐雾
涂盐热腐蚀
atmospheric plasma spraying
NiCrSiB alloy
anti corrosion coating
salt fog
salt-coated hot corrosion
