Study On Corrosion Behavior Of Nanocrystalline 304 Stainless Steel

304 stainless steel is a common stainless steel,and because of its widely used for production so it requires a well integrated performance.With the development of science and technology,people now pay more attention to the nano-materials.Nano-materials causes extensive attention of researchers in various fields because of its unique physical,chemical and mechanical properties.In this paper,the bulk nanocrystalline materials is prepared by using the deep rolling technology,and an ordinary cast stainless steel sets as a comparison of samples.In the experiment,mainly study the different corrosion behavior of nanocrystalline materials and the general cast of the bulk material in the Cl-containing solution.Stress corrosion corrosion tests were measured by using SCC-1 type slow strain rate test system for both 304 stainless steel in the concentration of 0.1mol/L,0.5mol/L,1.0mol/Land 1.5mol/LHCl,at the tensile rate 10-4mm/s conditions.The results showed that:the concentration of hydrochloric acid less than 0.5mol/L,nanocrystalline 304 stainless steel's stress corrosion resistance is superior to the ordinary cast 304 stainless steel;as the concentration of hydrochloric acid continues to increase,the ordinary cast 304 stainless steel and nanocrystalline 304resistance to stress corrosion were both decreased.Potentiodynamic polarization curves and AC impedance tests were measured by using the CHI604D ChemStation for both 304 stainless steel in the concentration of 0.1mol/L,0.5mol/L and 1.0mol/LHCl.The results showed that:in 0.1mol/L and 0.5mol/LHCl,nanocrystalline 304 stainless steel electrochemical corrosion resistant is superior to the ordinary cast 304 stainless steel;but in 1.0 mol/LHCl,the ordinary cast 304 stainless steel and nanocrystalline 304resistance to stress corrosion were both decreased.Potentiostatic polarization curves for both 304 stainless steel in the concentration of 0.1mol/L,0.5mol/L and 1.0mol/LHCl,through XPS analysis for the surface passivation membrane which was the formation of potentiostatic polarization curves can be concluded:nanocrystalline 304 stainless steel surface passivation membrane Cr3+ content is higher than that of ordinary cast 304 stainless steel,and in 1.0 mol/LHCl,ordinary cast and nanocrystalline 304 stainless steel surface passivation membrane Cr3+quite.Hot corrosion tests were measured by using SXL-1208 type programmable box furnace for both 304 stainless steel at the 650? and in the NaCl-Na2SO4 saturated molten salts.The results showed that:before 20h,ordinary cast 304 stainless steel corrosion rate is much higher than nanocrystalline 304 stainless steel,as time continues to grow,ordinary cast and nanocrystalline 304 stainless steel corrosion weight has stabilized,nanocrystalline 304 stainless steel corrosion weight gain is less than ordinary cast 304 stainless steel,and nanocrystalline 304 stainless steel surface oxide film was more stable and compact,nano-technology had improved the heat resistance of the material.The results of two kinds of 304 stainless steel in 6%FeCl3 solution showed that:nanocrystalline 304 stainless steel weight loss is much smaller than ordinary cast 304 stainless steel,and pitting holes formed on the surface was less and shallower than ordinary cast 304 stainless steel,nano-technology had improved the pitting resistance of the material.