Steel Corrosion Products Research Articles

Application of stripping voltammetry and microelectrodes in vitro biocompatibility and in vivo toxicity tests of AISI 316L corrosion products

Adsorptive stripping voltammetric procedures, using mercury film microelectrodes, were optimised and applied to quantify total iron, chromium and nickel in samples of osteoblast-like cells culture medium and mice organs (liver, kidney and spleen) obtained from, respectively, in vitro and in vivo 316L stainless steel corrosion products biocompatibility and toxicity studies. The methods were based on the pre-concentration of the iron-catechol complex by adsorption at the potential of -1.80 V (vs. Ag/AgCl), of the chromium-diethylenetriaminepentaacetic acid complex at -1.00 V or -1.15 V (vs. Ag/AgCl) and of the nickel-dimethylglyoxime complex at -0.70 V (vs. Ag/AgCl). The detection limits achieved for each metal ion (i) in the culture medium were 1.93x10(-8) mol/L Fe, 2.80x10(-10) mol/L Cr and 7.70x10(-9) mol/L Ni for a collection time of 30 s, 40 s and 10 s, respectively, and (ii) in the mice organ solutions were 1.37x10(-8) mol/L Fe, 1.54x10(-8) mol/L Cr and 1.58x10(-9) mol/L Ni for an adsorption time of 25 s, 25 s and 15 s, respectively. The accuracy of the proposed procedures was verified by comparison of the results obtained by adsorptive stripping voltammetry with those attained by atomic absorption spectrometry for the same set of samples and good agreement was found. The in vitro study showed that stainless steel corrosion products affect the expression of the osteogenic phenotype. The in vivo mice model, used to investigate the systemic effects provoked by the corrosion products per se, indicated that Fe, Cr and Ni are partially accumulated in the organs studied and that Ni induced the more significant morphological alterations.

Proliferation/differentiation of osteoblastic human alveolar bone cell cultures in the presence of stainless steel corrosion products.

Human osteoblastic alveolar bone cells were cultured for 28 days in control conditions and in the presence of three non-lethal concentrations of AISI 316L stainless steel (SS) corrosion products. Cells were exposed to SS corrosion products in two experimental situations: (i) in selected stages of the incubation time (during the first, second, third and fourth week of culture); and (ii) during the 28 days incubation period. Cultures were characterized for cell proliferation, total protein content, alkaline phosphatase activity (ALP) and ability to form mineralized deposits; culture media was analyzed for ionized calcium (Ca) and phosphorus (P) concentrations throughout the incubation period. The presence of SS corrosion products during the different stages of the incubation period did not significantly affect the cell proliferation; however, a significant dose-dependent deleterious effect was observed on the levels and pattern of ALP activity, concentration of ionized Ca and P in the culture medium and, also, ability to form mineralized deposits, especially in cultures exposed during the first and second week of culture (respectively, lag phase and exponential cell growth phase). Similar effects were observed in cultures exposed to the SS corrosion products during the 28 days incubation period. However, the presence of such products during the third week (when the mineralization process occurs) and, also, during the fourth week, resulted in little or no significant effects on the behavior of alveolar bone cells. Results suggested that SS corrosion products above certain non-lethal concentrations may disturb the proliferation/differentiation relationship of osteoblastic human alveolar bone cell cultures.

Mössbauer spectroscopy of corrosion products of mild steel due to microbiologically influenced corrosion

Corrosion products of mild steel exposed to four different cultures of sulfur reducing bacteria (SRB) grown in a synthetic medium have been studied by transmission Mossbauer spectroscopy (TMS). Cultures of SRB studied are two hydrogenase positive strains,Desulfovibrio desulfuricans (DD) andDesulfovibrio vulgaris (DV) and two hydrogenase negative strainsDesulfotomaculum orientis orientis (DO) andDesulfotomaculum nigrificans (DN). The corrosion products generated on the coupons as well as in the broth were studied. In all the cases, the corrosion products removed from coupons showed the presence of green rust 2 (GR2), ferrous sulfides, γ-FeOOH and superparamagnetic (SPM) α-FeOOH in different proportions. The corrosion products from the broth showed a symmetrical central doublet, which indicates the presence of γ-FeOOH and SPM α-FeOOH along with ferrous sulfides. The corrosion products from coupons suspended in sewage water also showed the presence of GR 2 and ferrous sulfides together with oxyhydroxides. FTIR spectrum supports the presence of these phases in corrosion products. The formation of GR 2 on coupons seems to be the first step for the SRB induced corrosion. The corrosion rate has been found in the order of DO>DN>DV>DD.

Effect of stainless steel corrosion products on in vitro biomineralization.

Osteoblast-like cell cultures have been used as in vitro models to study the interactions of bone tissue with biomaterials and their degradation products. This work reviews the effects of AISI 316L stainless steel (SS) corrosion products on the osteoblastic behavior of rat and human bone cell cultures. Results suggest that such products affect, in a dose-dependent manner, the proliferation and differentiation of osteoblastic cells; these effects depend on the developmental stage of the osteoblastic cells. Above certain nonlethal concentrations, SS corrosion products prevent the mineralization of the extracellular matrix, a process that reflects the complete expression of the osteoblastic phenotype.

Decreased consumption of Ca and P during in vitro biomineralization and biologically induced deposition of Ni and Cr in presence of stainless steel corrosion products.

The purpose of this study was to investigate the effects of 316L stainless steel (SS) corrosion products on the in vitro biomineralization process, because tissue necrosis, bone loss, impaired bone mineralization, and loosening of orthopedic implants are associated with ions and debris resulting from biodegradation. Rat bone marrow cells were cultured in experimental conditions that favored the proliferation and differentiation of osteoblastic cells and were exposed to SS corrosion products obtained by electrochemical means for periods ranging from 1 to 21 days. Quantification of total and ionized Ca and P, as well as Fe, Cr, and Ni, ions in the culture media of control and metal added cultures during the incubation period was performed to study the influence of corrosion products on the Ca and P consumption that occurs during the mineralization process. Control cultures and metal effects on cultures were evaluated concerning DNA content, enzymatic reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), and alkaline phosphatase (ALP) activity. Histochemical detection of ALP, Ca, and phosphate deposition, and examination of the cultures by scanning and transmission electron microscopy (SEM and TEM) were also performed. The presence of SS corrosion products resulted in impairment of the normal behavior of rat bone marrow cultures. Levels of Cr and Ni in the medium of cultures exposed to 316L SS corrosion products decreased throughout the incubation period, suggesting a regular deposition of these species; these results were supported by TEM observation of the cultures. Cultures exposed to the corrosion products presented lower DNA content, MTT reduction, and ALP activity and failed to form mineralized areas. These cultures showed negative staining on histochemical reactions for the identification of calcium and phosphate deposition and SEM and TEM examination did not show mineral globular structures or mineralization foci, respectively, which is characteristic of cultures grown in control conditions. These results suggest that metal ions associated with 316L SS are toxic to osteogenic cells, affecting their proliferation and differentiation.

Decreased consumption of Ca and P during in vitro biomineralization and biologically induced deposition of Ni and Cr in presence of stainless steel corrosion products

Decreased consumption of Ca and P during in vitro biomineralization and biologically induced deposition of Ni and Cr in presence of stainless steel corrosion products

Thermodynamic Equilibria in Aqueous Suspensions of Synthetic and Natural Fe(II)−Fe(III) Green Rusts: Occurrences of the Mineral in Hydromorphic Soils

Synthetic green rusts, GRs, are prepared by oxidation of Fe(OH)2 incorporating Cl-, SO42-, or CO32- ions. Eh−pH diagrams are drawn, and thermodynamic data are derived. A GR incorporating OH- ions, GR1(OH-), is suspected to exist like similar other M(II)−M(III) compounds. GRs form as corrosion products of steels, implying microbially induced corrosion. Mossbauer and Raman spectroscopies allowed the identification of GR in samples extracted from hydromorphic soils scattered over Brittany, France. This mineral has a varying Fe(III)/Fe(II) ratio. At Fougeres, it increases with depth till the oc currence of more oxidized ferric oxyhydroxide. In the same sites, soil solutions are collected and prevented from any oxidation and photoreduction. In large ranges of pH, pe, and Fe(II) concentration variations, soil solutions are in equilibrium with a Fe(II)−Fe(III) compound, a GR1 mineral with pyroaurite-like structure incorporating OH- ions and having the formula [FeII(1-x)FeIIIx(OH)2]+x·[xOH]-x ≡ Fe(OH)(2+x). Compu...

In vitro biomineralization by osteoblast-like cells I. Retardation of tissue mineralization by metal salts

The cytocompatibility of stainless steel 316L (SS 316L) corrosion products was investigated with particular focus on the dose- and time-effect of electrochemically dissolved SS and the corresponding separate metal ions on osteogenic bone marrow derived cells. Type AISI 316L stainless steel (Fe 63.9%, Cr 18.0%, Ni 12.5%, Mo 2.8%, Si 1.2%, Mn 1.6% and C 0.025%, weight for weight) was anodically dissolved in Hank’s Balanced Salt Solution (HBSS) and diluted to the following concentrations: 500 μg ml -1 of Fe, 122 μg ml -1 of Cr and 101 μg ml -1 of Ni, as estimated by atomic absorption spectrometry. Similarly, salt solutions containing 500 μg ml -1 of Fe (FeCl 3 · 6H 2O), 122 μg ml -1 of Cr (CrCl 3 · 6H 2O) or 101 μg ml -1 of Ni (NiNO 3) were prepared. All solutions were diluted 1:10 3, 1:10 4 and 1:10 5 and their effects on cell proliferation and function of rabbit bone marrow cells were studied up to 28 days of culture. Bone marrow cells (second subculture) were cultured in α-Minimal Essential Medium ( α-MEM) supplemented with 10% fetal bovine serum 10 -8 mol l -1 dexamethasone, 2.52×10 -4 mol l -1 ascorbic acid and 10 -2 mol l -1 β-glycerophosphate. The osteoblast response to the presence of metal ions was evaluated by biochemical assays (enzymatic reduction of MTT for evaluation of cell viability/proliferation, and estimation of alkaline phosphatase (ALP) activity) and histochemical assays (identification of ALP positive cells and calcium and phosphates deposits). Results suggest a decrease in the expression of the osteoblast phenotype in the presence of ion and alloy solutions. Stainless steel corrosion products elicited slight effects but the corresponding metal ions produced pronounced effects on the osteoblast phenotype, namely an alteration in the levels and temporal expression of ALP and lower and retarded tissue mineralization ability.

Evaluation of Steel Corrosion Products in Tropical Climates

Abstract Phase variations occurring in corrosion products obtained in steels exposed to different zones of tropical climate in Cuba and Venezuela were determined to establish their relationship to ...

Role of water adsorption and salt content in atmospheric corrosion products of steel

The corrosion products formed as a new phase in a metal-atmosphere system influence atmospheric corrosion mechanisms, particularly over a long term. Water adsorption in corrosion products is very important, because it determines the time during which corrosion occurs at metal-corrosion products interface. Adsorption isotherms of the corrosion products formed on steel exposed in a coastal and a rural atmospheres were obtained. The chloride, sulfate and bicarbonate concentrations in these products were also determined. A polymolecular adsorption mechanism was determined for corrosion products formed in a coastal environment, while a monomolecular adsorption takes place in corrosion products formed in a rural one. A notable difference between chloride concentration in corrosion products and chloride deposition rate determined by the dry plate method was determined. This situation was not the same in the case of sulfate ions. It means that corrosion takes place under very variable concentrations of chloride ions and in the presence of less variable concentrations of sulfate ions.

Inhibition and stimulation of enzymatic activities of human fibroblasts by corrosion products and metal salts

Fibroblasts from normal human skin were cultured for a period of 21 days in the absence or in the presence of metal ions. The effects of stainless steel (SS) corrosion products were compared to the effects of iron, chromium and nickel ions used either separately (Fe, Cr, or Ni solutions) or combined (Fe+Cr+Ni solution). At several periods of time (4, 7, 14 and 21 days) the cell cultures were analysed for the following parameters: (a) metal ion accumulation by atomic absorption spectrometry; (b) cell morphology and viability by the neutral red assay; (c) cell proliferation by DNA assessment, and enzyme activity by both (d) MTT reduction and (e) acid phosphatase activity. Results showed that SS-corrosion products and the corresponding metal ions combined at the same concentrations, Fe+Cr+Ni solution, had opposite effects on fibroblast cultures. In fact, SS-corrosion products caused no apparent effects on cell morphology nor on cell proliferation whereas Fe+Cr+Ni solution stimulated both neutral red uptake and cell proliferation. The enzymatic assays showed that SS-corrosion products caused inhibition of both MTT reduction and acid phosphatase activity in contrast to Fe+Cr+Ni solution which stimulated their activity. Furthermore, in all biological parameters studied, a strong association was observed between the effects of Fe+Cr+Ni solution and Cr alone, suggesting that Cr was the metal ion mostly involved in the stimulatory effects of the combined solution.

Damage to reinforced concrete due to reinforcement corrosion

The products of steel corrosion create volumetric expansion in the steel bars that damages the concrete. The effects on the rc elements are described in this paper. The damage of concrete by cracking which produces a variation of the tension distribution over the entire section and causes a variation of the bending rigidity and a reduction of the concrete-reinforcement bond due to a loss of confinement are shown. We also analyse the strength capacity of the rc sections with corroded reinforcement subjected to bending under static load by direct and inverse methods. Finally, the author describes the structural effects due to corrosion on elements resistant to shear and torsion.

Chromium accumulation and ultrastructural changes in the mouse liver caused by stainless steel corrosion products

Stainless steel (SS) corrosion products were obtained by electrochemical dissolution of SS type AISI 316L. Mice were injected subcutaneously with 0.5 ml of SS solution (containing 283 μg Fe, 69.3 μg Cr and 57 μg Ni) each 72 h, for 10 days or 14 days. After the treatment time, livers were removed and were analysed for: (a) liver wet weight; (b) contents in Fe, Cr and Ni; (c) histological and ultrastructural alterations. Results showed that the percentage of liver weight per animal body weight was significantly higher (p < 0.05) in SS-injected animals than in the control animals. The atomic absorption spectrometry analysis of dry livers showed that chromium, but not iron or nickel, had a significant increase (p < 0.05) in SS-treated mice compared to the control animals. No histopathological differences between 10 and 14 days of SS-injection could be detected, however, massive hepatic degeneration was observed in both groups when compared to the control. These histological changes in SS-treated mice were confirmed at the ultrastructural level, as hepatocytes exhibited an augmentation of vacuoles in their cytoplasm. These actual liver morphological alterations suggest that the hepatocyte function may be hampered, which constitutes a matter of some concern since liver is a blood filtering organ.

Studies on the permeability of the blood-testis barrier in stainless steel-administered mice

Previous trials performed in our laboratory have demonstrated that stainless steel corrosion products induced morphological changes in mice seminiferous cells. In this study the functional nature of the blood-testis barrier was investigated, in view of the extesive use of this metallic alloy in orthopaedic surgery. The uptake of horseradish peroxidase by the seminiferous tubules was used as a tracer method being exposed in vitro for different periods of time and observed at the ultrastructural level. Both boundary cells as well as Sertoli cells of experimental group absorbed the tracer, as manifested by vesicles and vacuoles filled with the reaction product, evidencing its role within the testis. Germ cells were also able in the uptake of this macromolecule. However, the tracer did not spread into the junctional complexes between neighboring Sertoli cells, at any interval of time used in this study, demonstrating the functional integrity of this barrier.

Stainless steel corrosion products cause alterations on mouse spleen cellular populations

Stainless steel is a metallic biomaterial commonly used in orthopaedic surgery. In this study we looked at the effects of stainless steel corrosion products on spleen, in order to evaluate their potential immunotoxicological effects. For this purpose stainless steel, type AISI 316L, was electrochemicallydissolved in a physiological salt solution. The final solution, containing 490 μg/ml Fe, 224 μg/ml Cr and 150 μg/ml Ni, was injected subcutaneously in mice. After several periods of time (4, 10 and 14 days) spleens were removed and analysed for: (a) their contents in Fe, Cr and Ni, (b) histological alterations, (c) enumeration of cellular populations. Results showed that stainless steel corrosion products accumulated in spleen, caused histological alterations, and induced changes in cellular populations. When compared to chromium and nickel, iron was the metal ion preferentially accumulated in spleen. The increase of the multinucleated giant cell population was accompanied by depletion of lymphocyte populations. This study indicates that stainless steel corrosion products can spread systemically and accumulate in spleen inducing histological and cellular alterations which may give rise to immunotoxicological consequences.

Use of a glass-carbon rotating disk electrode for the identification of corrosion products of steels

Use of a glass-carbon rotating disk electrode for the identification of corrosion products of steels

Mössbauer study of the corrosion products of 42CD4 steel in natural seawater

Mossbauer and X-ray studies of the corrosion products formed on 42CD4 steel plates immersed in natural seawater under atmospheric pressure showed that small particles of γ-FeOOH and α-FeOOH are the main constituents of the rust layer. Their Neel temperatures are estimated to be 39 and 280 K, respectively.

Mouse inflammatory response to stainless steel corrosion products

Corrosion occurs regularly following long-term implantation of stainless steel. Little is known about the inflammatory and immunological potential of stainless steel corrosion products. AISI 316L stainless steel was anodically dissolved in a physiologically solution, HBSS, through a chronoamperometric process by imposing an external constant current of 0.5 mA. The solution, containing 245 μg of Fe, 112 μg of Cr, 75 μg of Ni and 13 μg of Mo, was injected in the peritoneal cavity of male C57BL/6 mice. Five animals were used per survival period of time: 4, 16, 24, and 48 h, 1, 2, 4, 8 and 16 weeks. Three control mice per survival period of time were injected with HBSS. For each assay, peritoneal samples were analysed not only for the total number of cells but also for the percentages of macrophages, lymphocytes and polymorphonuclear (PMN) cells, which were estimated by differential counting on Wright-stained cytocentrifuge preparations. Our follow-up study showed that stainless steel corrosion products induced an acute inflammatory response for a period of one week as demonstrated by the influx of PMN cells and macrophages. In contrast neither a chronic inflammation nor an immune response was observed indicating that the stainless steel solution caused a minor tissue response.

X-ray diffraction and Fourier transform-infrared analysis of the rust formed by corrosion of steel in aqueous solutions

Chemical and structural properties of the rust formed by corrosion of steel in aqueous solutions were studied by X-ray diffraction and Fourier transform infrared (FT-IR) spectroscopy. The corrosion products of steel were generated in aqueous solutions of different electrolyte compositions at room temperature (20 °C) or in an autoclave at 120 °C. X-ray diffraction analysis showed the presence of different oxide phases in the rust, such as lepidocrocite, magnetite, ferrihydrite, goethite and haematite. In all samples, the presence of an amorphous fraction was detected. Ferrihydrite was detected only in the rust samples formed at 120 °C, The characteristic properties of the FT-IR spectrum of the ferrihydrite component in the rust were investigated. Phase compositions of the corrosion products depended on the formation temperature and the electrolyte composition of the aqueous solutions. The influence of chloride, nitrate or sulphate anions on the phase composition of the rust is discussed.

Effects of various metal substrata on accumulation ofPseudomonas aeruginosabiofilms and the efficacy of monochloramine as a biocide

Monochloramine at 4 mg·l−1 was used to treat biofilms of Pseudomonas aeruginosa grown in annular reactors on various metal substrata, including stainless steel, mild steel and copper. Disinfection of in situ biofilms was most efficient on the stainless steel slides. The treatment reduced viable cells in the biofilm on the stainless steel slides by more than 4 orders of magnitude after 60 min, while the same treatment reduced viable cells in the biofilms on the other slides (mild steel and copper) by only 2 orders of magnitude. Mild steel corrosion products retarded the disinfection of homogenized biofilm cells. The composition of steady state biofilms on the various substrata (before biocide treatment) differed. Biofilm on stainless steel slides had more viable cells but less extracellular polymeric substance (EPS). Biofilms on mild steel and copper slides had fewer viable cells but more EPS. Almost 95% of total cells in the biofilm on the copper slides were dead cells. The lower efficacy of disinfection ...