煤油流量对HVOF铁基非晶涂层组织与性能的影响

以工业原材料制备的FeCoCrMoCBY非晶粉末为喷涂材料,采用超音速火焰喷涂(HVOF)制备铁基非晶合金涂层。通过X射线衍射仪(XRD)、差示扫描热仪(DSC)、扫描电子显微镜(SEM)、维氏显微硬度计等测试方法,探讨煤油流量对涂层显微组织、微观结构及显微硬度的影响,并分析涂层与316 L不锈钢在1 mol/L HCl溶液中的动态极化特征。结果表明:涂层与基体结合良好,呈现典型的层状结构,非晶含量高,表现出比316 L不锈钢更高的耐腐蚀性能。其它参数一定时,煤油流量越高,涂层致密度越高,非晶含量先增多后减少,显微硬度先增大后减小;当氧气流量为50 m~3/L,煤油流量为26 L/h时,涂层非晶含量最高,为99.4%,孔隙率为1.51%,自腐蚀电流密度低,为5.62×10~(-6) A/cm~2,自腐蚀电位为-0.36 V,耐腐蚀性能表现最佳。

Effects of Kerosene Content on Microstructure and Properties of HVOF Fe-based Amorphous Coatings

Using the spray materials of FeCoCrMoCBY amorphous powder with industrial raw materials,the Fe-based amorphous coating was fabricated by high velocity oxy-fuel spraying. The effect of kerosene content on microstructure and microhardness of the coatings was investigated by X-ray diffraction, differential scanning calorimetry, scanning electron microscope and vickers microhardness tester, respectively. The corrosion resistance of the coatings was studied by potentiodynamic polarization test in HCl solution of 1 mol/L. The results show that the coatings exhibit good adhesion with the substrate, typical lamellar structure, high amorphous content, and more excellent corrosion resistance than 316 L stainless steel. With the increase of kerosene content, the coating density increases, its amorphous content and microhardness first increase and then decrease when other parameters are fixed. When the oxygen flow is 50 m³/L and kerosene content is 26 L/h, the coating amorphous content attains the highest, which is 99.4%. The porosity is 1.51%, and the low corrosion current density and high corrosion potential are about 5.62×10^-6 A/cm² and -0.36 V, respectively. Thus, the coatings show excellent corrosion resistance.