Effect Of Surface Treatment On High Temperature Oxidation Resistance Of Stainless Steel

304 stainless steel is used to manufacture corrosion resistance equipment and important metal components,which is widely applied in general chemical equipment,nuclear energy and other fields.In the actual environment,high-temperature oxidation not only shortens the service life of stainless steel,but also reduces its application range.So it is of great significance to prepare anti-high temperature oxidation coating on the surface of stainless steel.In this paper,single and composite films were deposited on the surface of 304 stainless steel by electrodeposition-pyrolysis method.The high temperature cyclic oxidation experiment was carried out at 900?for 100h.Through the analysis of oxidation kinetics curves,SEM and XRD results,conclusions were drawn as follows:?1?The single films prepared by electrodepositation-pyrolysis obviously improved the high temperature oxidation resistance of 304 stainless steel.When the deposition voltage was 25V and the electrodeposition solution concentration was 0.10mol/L,the single Cr2O3and Al2O3 films had better high-temperature oxidation resistance and protective Cr2O3scale were formed on the surface of the samples.When the deposition voltage was 25V and the electrodeposition solution concentration was 0.03mol/L,the single Ce2O3 film had good oxidation resistance at high temperature and the protective Cr1.3Fe0.7O3 scale was formed.?2?The composite films prepared by electrodepositation-pyrolysis significantly improved the high temperature oxidation resistance of 304 stainless steel.The mass gain and spallation of Cr2O3-Al2O3 film prepared with 2:1 molar concentration ratio of Cr?NO3?3 and Al?NO3?3 under 25V and 60s electrodeposition parameters were respectively23.6%and 10.4%those of the undeposited samples.?3?The oxidation resistance of Cr₂O₃-Al₂O₃,Cr₂O₃-Ce₂O₃,Al₂O₃-Ce₂O₃ composite film was superior to that of single films.Protective Cr_1.3Fe_0.7O₃ and NiCr₂O₄ scales were generated on the surface of 304 stainless steel deposited with Cr2O3-Al2O3 film which provide excellent protection to resist high temperature oxidation.Cr2O3 scale belongs to metal deficiency type.The change of oxygen partial pressure at the environment greatly affects by the oxidation kinetics of oxidation film.The vapor pressure of A12O3 is lower than that of Cr₂O₃,which reduces volatilization.Ce in Cr₂O₃-Ce₂O₃ and Al₂O₃-Ce₂O₃films can only reduce the critical aluminum or chromium content of Al2O3 and Cr2O3,which promote the growth of protective oxide scale.