超高速激光熔覆Stellite 6涂层的抗汽蚀及冲蚀性能  

Anti-cavitation and Erosion Resistance of Stellite 6 Coating by Ultra-high Speed Laser Cladding

作　　者：张林 刘刚[2] 曾东 李勇[2] 刘福广[2] 张璐 谢长宁 ZHANG Lin;LIU Gang;ZENG Dong;LI Yong;LIU Fu-guang;ZHANG Lu;XIE Chang-ning(Nanyahe Branch of Sichuan Power Generation Co.,Ltd.,CHN Energy,Chengdu 610027,China;Xi'an Thermal Power Research Institute Co.,Ltd.,Xi'an 710054,China)

机构地区：[1]国家能源集团四川发电有限公司南桠河水电分公司,成都610027 [2]西安热工研究院有限公司,西安710054

出　　处：《表面技术》2022年第4期167-175,共9页Surface Technology

摘　　要：目的提高水利机械常用ZG06Cr13Ni4Mo马氏体不锈钢的抗汽蚀、冲蚀性能。方法采用超高速激光熔覆技术在ZG06Cr13Ni4Mo马氏体不锈钢基体上制备Stellite 6涂层。用X射线衍射仪(XRD)分析涂层物相。用扫描电子显微镜(SEM)及能谱(EDS)研究涂层组织结构特征。用HV-1000型显微硬度计测试了涂层的硬度分布。用超声振动汽蚀试验设备研究了涂层抗汽蚀性能。用喷射型冲蚀磨损试验机研究了涂层的抗冲蚀性能。通过SEM分析试样表面的汽蚀、冲蚀形貌。结果STELLITE 6涂层厚度约为400μm,主要由FCC结构的γ-Co枝晶固溶体与Cr_(23)C_(6)共晶碳化物组成。涂层致密程度较高,涂层中Co、Cr的质量分数分别为55.6%、27.6%,完美地继承了粉末的原始成分。Stellite 6涂层的显微硬度为570HV0.1,与不锈钢基体相比提升了2.3倍,热影响区深度仅为70μm。随着超声振动汽蚀试验周期的延长,涂层与不锈钢失重线性增加,冲蚀24 h后涂层的损失量为1.1 mg,不锈钢的损失量为8.0 mg。经过180 s的小角度(30°)冲蚀试验后,Stellite 6涂层的损失量为9.1 mg,不锈钢的损失量为13.5 mg。结论超高速激光熔覆Stellite 6涂层很好地保留了熔覆层粉末的原始成分,涂层组织结构致密、稀释率低、热影响区窄,高硬涂层显著提高了水利机械常用ZG06Cr13Ni4Mo马氏体不锈钢的抗汽蚀及冲蚀性能。The work aims to improve the anti-cavitation and erosion resistance of ZG06Cr13Ni4Mo martensitic stainless steel commonly used in hydraulic machinery.The Stellite 6 coating was prepared on the ZG06Cr13Ni4Mo martensitic stainless steel substrate using ultra-high-speed laser cladding.X-ray diffractometer(XRD)was used to analyze the coating phase,scanning electron microscope(SEM),the energy dispersive spectrometer(EDS)to study the structural characteristics of the coating,the HV-1000 microhardness tester to test the coating hardness distribution,and the ultrasonic vibration cavitation test equipment to study the anti-cavitation of the coating,as well as the erosion resistance of the coating studied by the jet erosion wear tester and the cavitation and erosion morphology of the sample surface analyzed by SEM.An Stellite 6 coating with a thickness of about 400μm was prepared and mainly composed of theγ-Co dendritic solid solution with FCC structure and the Cr_(23)C_(6) eutectic carbide.The coating was dense,and its contents of Co and Cr were 55.6wt.%and 27.6wt.%respectively,which perfectly retain the chemical composition of the powder.The microhardness of Stellite 6 coating was 570HV0.1,2.3 times that of stainless steel,and the depth of the heat-affected zone(HAZ)was only 70μm.The weight loss increased linearly with test duration increased,after 24-hour ultrasonic vibration cavitation test,the weight loss of the coating was 1.1 mg,and 8.0 mg for that of stainless steel.After the 30°erosion test for 180 s,the weight loss of the Stellite 6 coating and the stainless steel were 9.1 mg and 13.5 mg,respectively.Thus,the Stellite 6 coating prepared by ultra-high-speed laser cladding retains the chemical composition of the Stellite 6 powder and with a dense structure,low dilution rate and a narrow heat-affected zone.Besides,the high hardness coating significantly improves the cavitation and erosion resistance of the ZG06Cr13Ni4Mo martensitic stainless steel commonly used in hydraulic machinery.

关 键 词：超高速激光熔覆 Stellite 6涂层 显微结构 汽蚀 冲蚀 

分 类 号：TH117[机械工程—机械设计及理论]