Surface analytical and electrochemical study on the role of adsorbed chloride ions in corrosion of stainless steels

Self Cite

Nowadays there is a strong demand to replace CrNi stainless steels used for biomedical applications such as brackets in orthodontics with a new generation of more biocompatible austenitic, nickel-free alloys. The aim of this work is the investigation of the growth and stability of the surface films formed on DIN 1.4456 Ni-free stainless steel (18% Cr, 18% Mn, 2% Mo) in artificial saliva (pH 7.9) at 37°C by electrochemistry and XPS surface analyses and the assessment of the ions that leach from the steel. These results show that the open circuit potential asymptotically increases and the corrosion current density decreases from 1 to 24 hours exposure time to the artificial saliva. XPS provides evidence that the surface film present on the surface after mechanical polishing transforms into a passive film that becomes progressively enriched in Cr(III) oxy-hydroxides whereas iron and manga¬nese oxides are depleted. It is found that the instantaneous corrosion rate decreases exponentially with the amount of Cr(III) in the passive film. The results are discussed regarding the biocompatibility, thus the release of ions into solution, of the new nickel-free stainless steel. Based on the results presented in this paper and literature evidence a comprehensive model is proposed that substantiates the biocompatibility of these alloy

Section: Methodsmentioning

confidence: 99%

Electrochemical and XPS surface analytical study on the reactivity of Ni‐free stainless steel in artificial saliva

Elsener

Pisu

Fantauzzi

et al. 2016

Self Cite

“…7(a)], suggesting the existence of Fe, C, S, P, and O on the specimen surface. Chemical compounds 14–23, such as FeOOH, hydrocarbons, Fe 2 (SO 4 ) 3 , FeSO 4 , FePO 4 , FeCO 3 , and P 4 S 10 , were detected in all specimens shown in Fig. 7(b–e).…”

Section: Resultsmentioning

confidence: 84%

Effect of aluminum on the corrosion resistance of low‐alloy steel in 10 wt% sulfuric acid solution

Nam¹,

Kim²,

Kim³

2011

The aqueous corrosion behavior of low-alloy steel with aluminum contents was examined in a 10 wt% H 2 SO 4 (pH 0.13) solution using electrochemical techniques and surface analyses. The corrosion resistance of the new alloy steel was evaluated in terms of electrochemical parameters, such as passive current density, film, and charge transfer resistances. The results showed that a high Al content in the steel imparted better passivation behavior resulting in a lower corrosion rate. It related to the enrichment of iron carbonate and hydrocarbon by the dissolution of the carbide phase.

“…Fe2p 3/2 spectra in XPS was decomposed into four contributions: Fe metal, iron(II) oxide, iron(III) oxide, and oxide–hydroxide 33–35. Figures 9 and 10 are the decomposition results of Fe2p 3/2 spectra for the steel samples.…”

Section: Resultsmentioning

confidence: 99%

1,3‐Bis‐dibutylaminopropan‐2‐ol as inhibitor for reinforcement steel in chloride‐contaminated simulated concrete pore solution

Liu

Chen

Cai

et al. 2012

An organic compound, 1,3‐bis‐dibutylaminopropan‐2‐ol (BDAP) was prepared and tested experimentally as inhibitor for reinforcement steel in simulated concrete pore solution. The electrochemical behavior of carbon steel electrodes immersed in simulated pore solutions with different concentration of BDAP was investigated by electrochemical measurements. Adsorption isotherm was determined based on the inhibition efficiency. The surface composition was evaluated via X‐ray photoelectron spectroscopy (XPS) as well in order to verify the presence and adsorption property of BDAP. The results showed that BDAP could effectively suppress the anodic process of carbon steel corrosion and the inhibition efficiency was improving with the increase of inhibitor concentration. BDAP could adsorb on carbon steel surface according to Langmuir adsorption isotherm. XPS spectrum certified the existence of BDAP on the steel surface.