In recent years, many researches have been done on anodizing austenitic stainless steels and results indicate significant advances in this field. In this study, effect of sample passivation and pulse current parameters on the anodic layer properties of the anodizing process on AISI 304 austenitic stainless steel was investigated. In this regard, the effects of pulse type, duty cycle time, duty cycle length and passivation of samples on the quality of anodic layer were investigated. The anodizing process was carried out in ethylene glycol solution containing 0.1 mol.dm -3 ammonium fluoride and 0.1 mol.dm -3 water at a constant current density100 A.m -2 and Passivation of the samples was carried out in 35 volume percent hydrogen peroxide solution. All of four variables increased the thickness of the anodic layer resulted from anodizing process and totally pulse anodizing increased the anodic layer thickness. The variables had different effects on increasing the anodic layer thickness and effect of pulse type and duty cycle time variables on increasing anodic layer thickness have been more than other two variables. The results of this study indicated that the anodic layer roughness of the anodized samples by pulsed current method created more roughness than the direct current. Also, passivation of the samples makes the anodic layer rougher in both direct current and pulse current anodizing processes. average roughness of anodized specimens was obtained 0.04 by direct current and pulse current anodizing process, which average roughness of specimens are in range of superfinished parts. Three-point bending method was used to evaluate adhesion of anodic layer of anodized samples and Appropriate adhesion of bent anodic layer obtained from both direct current and pulse current anodizing Confirmed by optical microscope images. The highest hardness of the anodized samples was obtained by using pulse-reverse current method. In order to create the colored anodic layer in the present research, three methods have been achieved using pulsed anodizing to create the golden anodic layer. Keywords: Anodizing, Anodic layer, Stainless steel, Pulse anodizing, Oxide coating, Porous layer
