煤液化减压阀的工作条件非常苛刻,对其阀座、阀芯等关键部件在高温、高压差、高固态浓度流体冲蚀条件下的抗冲蚀磨损性能及使用稳定性提出了极高的要求.CVD金刚石涂层具有接近天然金刚石的优异性能,非常适合用于煤液化减压阀关键部件的表面强化.采用热丝CVD法在硬质合金阀座及阀芯主要的受冲蚀表面沉积获得了金刚石涂层,为保证沉积过程中温度分布及制备获得的金刚石涂层厚度分布的均匀性,针对阀座和阀芯的不同结构,分别采用了直拉热丝穿孔和平行阶梯式排列两种不同的热丝排布方式.采用扫描电子显微镜(SEM)和Raman谱仪对沉积获得的金刚石涂层进行了性能表征,结果表明,在阀芯和阀座表面均沉积获得了一层连续、厚度均匀、颗粒度约为3 ～5 μm、具有典型的金刚石特征的高质量金刚石涂层.将CVD金刚石涂层煤液化减压阀关键部件应用在实际煤液化工况条件下试运行,其使用寿命超过了1 200 h,比普通同类部件的使用寿命提高了3倍以上.%Relief valves used in the coal liquefaction equipment are running in an extremely harsh environment. Diamond film is potentially used as wear-resistant and protective coating for the relief valve components due to its outstanding mechanical and tribological properties. A layer of high-quality diamond film is deposited on the working surface of conventional WC-Co cemented carbide relief valve spool and valve seat, using the hot filament chemical vapor deposition (HFCVD) technique, with two different types of hot filament arrangements. The fabricated CVD diamond coated relief valve components are characterized using scanning electron microscope (SEM) , X-ray diffraction spectroscopy (XRD) , and Raman spectroscopy. The results exhibit that a layer of continuous, homogeneous diamond films(3 ~5 (μm) has been deposited. Furthermore, the performance of fabricated relief valve components is evaluated under actual working conditions and the working lifetime is largely elongated up to 1200 hours, as more than three times as that of conventional relief valve components.
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