超音速火焰喷涂FeCrSiB涂层的腐蚀行为

采用超音速火焰(high velocity oxygen fuel,HVOF)喷涂技术在Q235钢基体上制备了FeCrSiB合金涂层.利用X射线衍射仪、扫描电子显微镜、电化学工作站等设备对涂层的显微组织结构和耐腐蚀性进行了研究.结果表明,采用HVOF喷涂技术制备的FeCrSiB涂层结构致密,孔隙率为0.65%,与基体结合良好.FeCrSiB涂层在3.5%NaCl溶液、1 mol/L HCl溶液和1 mol/L NaOH溶液中都经历了活性溶解-钝化-过钝化的过程,且该涂层在3.5%NaCl溶液和1 mol/L HCl溶液中的耐腐蚀性能要优于镀铬层,在1 mol/L NaOH溶液中的耐腐蚀性能低于镀铬层.

Corrosion behavior of FeCrSiB alloy coatings prepared by HVOF thermal spraying

FeCrSiB alloy coatings were prepared on Q235 steel substrate by high velocity oxygen fuel (HVOF) spray process. The microstructure and corrosion resistance of the deposited coatings were investigated by means of X-ray diffraction (XRD),scanning electron microscopy (SEM) and corrosion resistance evaluation equipments. It was found that the coatings exhibited dense structure with the porosity of 0.65% and compact bonding with the substrate. Electrochemical tests indicate that the FeCrSiB coatings underwent the subsequent processes of active solution,passivation,and repassivation in 3.5% NaCl solution, 1 mol/L HCl solution and 1 mol/L NaOH solution. Compared to the electrodeposited chromium coatings,FeCrSiB coating had better corrosion resistance in 3.5% NaCl solution and 1 mol/L HCl solution but worse corrosion resistance in 1 mol/L NaOH solution.