Enhancing General Corrosion Resistance of Biomedical High Nitrogen Nickel-Free Stainless Steel by Nitric Acid Passivation

Abstract

A systematic study of nitric acid passivation was investigated to enhance the general corrosion resistance of biomedical high-nitrogen nickel-free stainless steels (HNSs). After passivation, the corrosion rate of HNS could dramatically reduce to 1/20 of the untreated in 37 °C 0.9 wt% NaCl solutions. Then, the passive film on HNS was analyzed by X-ray photoelectron spectroscopy. It was found that chromium enrichment in the passive film and nitrogen enrichment in the film/metal interface contributed to the improvement in general corrosion resistance of HNS.

Corrosion Behavior of Sensitized AISI 304 Stainless Steel in Acid Chloride Solution

“…For this specimen, the positive effect of the high-temperature oxides chemical removal was registered [ 16 , 17 ]. Nitric acid as a part of the pickling solution could strengthen the passive surface film [ 30 , 31 , 32 ], which partially retained its protectiveness. This was reflected in the curve with a narrow passivity region.…”

“…This was reflected in the curve with a narrow passivity region. The authors [ 30 , 31 , 32 ] recorded that nitric acid passivation contributes to the changes in the surface chemistry by oxidation of chromium and dissolution of iron oxides. The result is an increase in the Cr/Fe ratio.…”

Biomedical Alloys and Physical Surface Modifications: A Mini-Review

“…Stainless steel after acid immersion and anodizing treatment can exhibit the lowest thickness of the fibrous capsule membrane [ 33 ]. Yang et al [ 34 ] investigated the effect of nitric acid passivation on high-nitrogen nickel-free stainless steels. The corrosion rate can be decreased by this passivation.…”