超音速等离子喷涂高压阀门密封面涂层多参数耦合优化及服役性能研究

Multi-Parameter Coupling Optimization and Service-Performance Study on Coatings for High-Pressure Valve Sealing Surfaces by Supersonic Plasma Spraying

摘要: 针对闸板PFF65-140型高压阀门在高压、水油汽多介质复杂工况下密封面涂层易失效的工程问题，以12Cr13、30CrMo两种阀门常用合金钢为基体，碳化钨(含Co)为喷涂材料，采用L₃₂(4¹⁰)正交试验方案，选取主气流量(煤油流量、煤油压力、氧气流量、氧气压力)、喷涂距离(枪距)、粉末粒径(送粉克数)、送粉速率(送粉转速)、气体流量比(载气流量、燃烧室压力、载气压力)共5类因素10个工艺参数，每个因素设置4个水平，系统研究多参数耦合对涂层结合强度、表面硬度、耐磨损性能、耐腐蚀性能及微观结构的影响规律。通过极差分析与方差分析量化各工艺参数的影响权重与显著性，采用加权综合评分法确定适配不同工况的最优工艺参数组合。已完成的代表性试验结果表明：优化参数下涂层结合强度可达75 MPa，表面硬度可达1350 HV，均显著满足高压阀门密封面服役要求。研究建立了工艺参数与涂层性能的定量关联模型，为高压阀门密封面超音速等离子喷涂工艺标准化提供了系统的数据支撑。

Abstract: Aiming at the engineering problem of easy failure of sealing-surface coatings for PFF65-140 gate valves under complex high-pressure conditions with mixed water-oil-steam media, 12Cr13 and 30CrMo alloy steels (commonly-used valve substrates) and cobalt-containing tungsten-carbide spray powder were adopted in this work. An L₃₂(4¹⁰) orthogonal test scheme was designed. Five categories containing ten process parameters were selected, including main-gas flow (kerosene flow, kerosene pressure, oxygen flow, oxygen pressure), spraying distance (gun-to-substrate distance), powder particle size (powder feed mass), powder feed rate (powder-feed rotational speed), and gas-flow ratio (carrier-gas flow, combustion-chamber pressure, carrier-gas pressure). Each factor was set at four levels. The coupling effects of multiple parameters on coating properties including bonding strength, surface hardness, wear resistance, corrosion resistance and microstructure were systematically investigated. Range analysis and variance analysis were employed to quantify the influence weight and statistical significance of each process parameter. A weighted comprehensive-scoring method was used to obtain the optimal parameter combinations for different service conditions. Representative experimental results show that the coating achieves a bonding strength up to 75 MPa and surface hardness up to 1350 HV under optimized parameters, which well satisfies the service requirements of high-pressure valve sealing surfaces. A quantitative correlation model between process parameters and coating performance is established, providing systematic data support for process standardization of supersonic plasma spraying for high-pressure valve sealing surfaces.