Steel In Aqueous Media Research Articles

Surface characterization and electrochemical corrosion behaviour of 304 stainless steel in aqueous media

A formulation consisting 100 ppm of 3-phosphonopropionic acid, 50 ppm of Zn2+ and 150 ppm of Tween 80 (polyoxyethylene sorbitan monooleate) offered 97.4% inhibition to the corrosion of 304 austenitic stainless steel immersed in a groundwater environment. This formulation functioned as a mixed inhibitor. The protective film was analysed by luminescence, XRD and FTIR spectra and pit morphology and was also observed by scanning electron microscopy.

A methodology for the construction of the erosion-corrosion map in aqueous environments

For the erosion of alloys under aqueous conditions, there have been some recent attempts to identify the transitions between the erosion-corrosion regimes using laboratory results. Such transitions can be superimposed on an erosion-corrosion map as a function of the main corrosion and erosion variables. Defining the magnitude of the wastage rate on such maps enables the relevant process parameters involved in the damage process to be optimized. The object of this work was to model the erosion-corrosion behaviour of mild steel exposed to an aqueous solution containing alumina particles. The results were used to identify the transitions between the erosion-corrosion regimes on erosion-corrosion mechanism maps. Process control maps, which show the magnitude of the wastage rate, were also constructed using such an approach. This paper describes the basis of the mathematical models used to construct the boundaries on the maps. The effects of particle size, flux, and solution pH on such boundaries are demonstrated. In addition, a qualitative comparison is made between the results of the model, and a series of slurry erosion-corrosion tests of mild steel in aqueous media.

Effect of stresses on the electrochemical corrosion of steel in aqueous media

We investigate the effect of mechanical stresses on the rate of corrosion of 40Kh steel in aqueous media. The dependence of the rate of corrosion of the steel in the pH range 2–14 is corroborated.

Electrosynthesis of strongly adherent polypyrrole coatings on iron and mild steel in aqueous media

Strongly adherent polypyrrole (PPy) films have been obtained by electropolymerization of pyrrole on pretreated iron and mild steel. Several chemical pretreatments of the metal surfaces have been compared. The results show that a treatment by 10% aqueous nitric acid inhibits iron dissolution without preventing the pyrrole oxidation. Very adherent thickness-controlled PPy films were obtained at constant-current in various aqueous media containing Na 2SO 4, K 2C 2O 4 or KNO 3. A maximum coulombic efficiency of 95% was obtained in the presence of KNO 3 for a current density lower than 10 mA/ cm 2, but dropped to 70% and 50%, in the presence of Na 2SO 4 and K 2C 2O 4, respectively, and for a current density between 2 and 4 mA/cm 2.

Stability in Aqueous Media of 316L Stainless Steel Films Deposited on Internal Reflection Elements

Thin films of 316L stainless steel were sputter-deposited on cylindrical internal reflection elements (IREs) made of germanium. These films are intended for use in Fourier transform infrared (FT-IR) spectroscopy studies on the stability of stainless steel in aqueous media. In these deposits the films tend to peel off the substrate when immersed in water, probably due to galvanic corrosion at the metal/substrate interface. Deposition of a 2-nm-thick layer of chromium oxide on the substrate prior to the deposition of the steel was beneficial on three counts. It provided an electrically insulating layer, it enhanced adhesion, and it solved the steel/germanium incompatibility problem. It was also found that annealing the substrate prior to deposition remarkably enhances the film adhesion and improves the optical properties of the substrate. The microstructure, the topography, and the chemical composition of the films were characterized by scanning and transmission electron microscopy, Auger electron spectroscopy, and atomic force microscopy. The only significant difference between the austenitic stainless steel target material and the film is that the crystalline structure of the film is body-centered cubic. The optical properties of the system germanium/metallic film/water were studied and calculated with the help of a computer program. The absorbance of the water bands in the IR range was measured in coated Ge-IRE.

Passive films on stainless steels in aqueous media

The purpose of this paper is to provide a syntheses of experimental results regarding films formed on the surface of stainless steels. Such syntheses are attempted for the environments most studied. In each case the overview is presented with reference to the most important papers. Conflicting data are also presented and discussed. Based on the results of the prior studies, a four region model is proposed to describe the surface passive film and its breakdown.

Processing and properties of FeMnAl alloys

Alloys based on the FeMnAl system with and without carbon and silicon additions have been produced in order to examine their fabricability, mechanical properties and especially their corrosion resistance in aqueous solutions. In particular, casting, hot working, cold rolling, welding, heat treatment, tensile properties and abrasion resistance have been examined. Corrosion testing entailed immersion tests in tap water, synthetic mine water and salt solution. Potentiodynamic polarization scans were performed for mine water, salt solution and 1 N H 2SO 4. The behavior of various FeMnAl-based alloys has been compared with those of mild steel and corrosion-resistant steels. Although the alloys examined have some desirable properties their poor corrosion resistance makes them unacceptable as substitutes for conventional stainless steels in aqueous media.

Corrosion-mechanical strength of 60Kh3G8N8V steel in aqueous media

Corrosion-mechanical strength of 60Kh3G8N8V steel in aqueous media

Corrosion Behaviour of Borided and Nitrided Steels in Aqueous Media

Case hardening may result in a considerable extension of the life of machine parts subjected to the simultaneous action of wear and aqueous corrosion, provided that the resistance of the hardened surfaces against corrosion attack is at least equal or superior to that of the base material. The present work is devoted to the effect of boriding and nitriding on the corrosion resistance of cast iron, mild steel and some stainless steels under different environmental conditions.The results from electrochemical and conventional corrosion tests show that corrosion rates of nonalloyed iron-based materials, depending on the nature of the corrosive environment, are either decreased or not significantly influenced by boriding or nitriding. However, both nitriding and boriding may lead to a loss of corrosion resistance of stainless steels.

Electrochemical Behavior of Zinc and Steel In Aqueous Media–Part II

Experience has shown that in most aqueous solutions zinc is anodic to steel and that the corrosion resistance of zinc coated steel is enhanced by the resultant electrochemical protection. Under cer...

Electrochemical Behavior of Zinc and Steel In Aqueous Media

Electrochemical Behavior of Zinc and Steel In Aqueous Media