Corrosion Penetration Rate Research Articles

Physics and Chemistry Test on Aluminum-Based Composite Materials as an Alternative Material for the Manufacture of Brake Drum

One of the components of the vehicle are of particular interest is the brake system , because its main function is to stop the rotation axis, set the axis of rotation and to prevent unwanted rotation. One classification system is the brake drum that has been widely made of cast iron, cast iron and cast steel special. This study makes brake drum of composite materials aluminum-based, with reinforcement is silicon carbide (SiC), obtained optimum composition of 15%, so it is written (Al-Si)-SiC/15%. Physics testing includes testing of thermal conductivity and thermal expansion coefficient, and Chemistry testing the corrosion penetration rate when the test material was coating with regular polish, with chrome, with nickel and with nickel + chrome. The final results showed that the value of conductivity and thermal expansion coefficient of the composite material is lower than cast iron, aluminum and other alloys. That is pretty good heat resistance when applied to brake drum material. The lowest of corrosion penetration rate on coating material with a layer of Ni-Cr.

Physics and Chemistry Test on Aluminum-Based Composite Materials as an Alternative Material for the Manufacture of Brake Drum

One of the components of the vehicle are of particular interest is the brake system , because its main function is to stop the rotation axis, set the axis of rotation and to prevent unwanted rotation. One classification system is the brake drum that has been widely made of cast iron, cast iron and cast steel special. This study makes brake drum of composite materials aluminum-based, with reinforcement is silicon carbide (SiC), obtained optimum composition of 15%, so it is written (Al-Si)-SiC/15%. Physics testing includes testing of thermal conductivity and thermal expansion coefficient, and Chemistry testing the corrosion penetration rate when the test material was coating with regular polish, with chrome, with nickel and with nickel + chrome. The final results showed that the value of conductivity and thermal expansion coefficient of the composite material is lower than cast iron, aluminum and other alloys. That is pretty good heat resistance when applied to brake drum material. The lowest of corrosion penetration rate on coating material with a layer of Ni-Cr.

Unification of the Quadratic Model Equations of the Inhibition Characteristics of Acidified Ocimum Basilicum on the Corrosion Behaviour of Mild Steel

An attempt has been made at unifying the resulting quadratic models from the study of the correlation behavior of the inhibition characteristics of acidified ocimum basilicum on conventional mild steel. Weight-loss corrosion technique was employed in obtaining the corrosion penetration rate using the equation: cpr = . Subsequently, the quadratic models were developed by using a computer-aided statistical modeling technique (International Business Machine (IBM)’s SPSS version 17.0). The results obtained showed a nearly perfect positive correlation with a correlation coefficient in the range of 0.986 ≤ R ≤ 0.996 which depicts that R ≥ 1. Also, the coefficient of determination fell within the range of 0.972 ≤ R2 ≤ 0.992 showing that approximately 97% to 99% of the total variation in passivation rate was accounted for by corresponding variation in exposure time, leaving out only between 3% and 1% to extraneous factors that are not incorporated into the model equations. The equations were further unified into a generalized form using MathCAD 7.0 and the resulting equation was y = 1.032 － 0.002t + 1.899 × 10-6t2 with a R2 value of 0.935 indicating a well-correlated relationship. With this, a new frontier on corrosion studies has emerged typifying a classical departure from previously long-held assumption that corrosion behaviours at room temperature were only logarithmic.

A plastic Ni-free Zr-based bulk metallic glass with high specific strength and good corrosion properties in simulated body fluid

The mechanical properties at room temperature and the corrosion behavior in simulated body fluid (PBS) at 37°C of a Ni-free Zr62.3Cu22.5Fe4.9Al6.8Ag3.5 bulk metallic glass (BMG) were investigated. This BMG exhibits a good room temperature plasticity of 8%, a yield strain of 1.9% and a high fracture strength of about 1800MPa. Interestingly, the novel Zr-rich BMG possesses a specific strength (σ/ρ) of about 280MPacm3/g higher than that of conventional biomedical Ti6Al4V alloy and 316L stainless steel. In addition, this alloy also has a high corrosion resistance with a low corrosion penetration rate in simulated body fluids (PBS). The present Ni-free Zr-rich BMG with a critical diameter above 1cm, together with the high specific strength, large plasticity and good corrosion resistance in PBS, has excellent potential in biomedical applications.

Characterization and Prediction of Chemical Inhibition Performance for Erosion-Corrosion Conditions in Sweet Oil and Gas Production

The effects of sand erosion on inhibitor performance have been examined in a flow loop using an impinging jet test cell and different techniques such as long-term weight loss (WL), linear polarization resistance (LPR), potentiodynamic polarization (PDYN), 3-D profilometry, and electrochemical impedance spectroscopy (EIS). Inhibition mechanisms and the relation between inhibitor concentration and corrosion penetration rate are described by the Flory-Huggins, Frumkin, Temkin, and Langmuir adsorption isotherms. Flow loop tests indicated that sand particle erosion can decrease the efficiency of an imidazoline-based inhibitor by removing the inhibitor protective layer from the surface. Therefore, an increased concentration of inhibitor is needed during sand production to achieve the same effectiveness. It was shown that an inhibitor adsorption isotherm can be integrated into a mechanistic model for prediction of carbon dioxide (CO2) corrosion to predict CO2 corrosion rates as a function of inhibitor concentration. Also, the inhibitor adsorption isotherm has been modified as a function of erosivity to predict the effect of erosivity on corrosion inhibition. One novel approach is discussed for predicting the inhibited erosion-corrosion rate based on the modified inhibitor adsorption isotherms combined with mechanistic models for predicting CO2 corrosion rates and sand particle erosion rates.

A Study on Effect of Coarse Aggregate Type on Concrete Performance

This study reports the findings of an experimental investigation conducted to study the effect of two types of coarse aggregates on the performance of concrete in terms of compressive strength, modulus of elasticity, and steel-corrosion penetration rate. For this purpose, 27 concrete mixtures were prepared from each type of coarse aggregates by varying key mixture parameters, namely water/cementitious materials ratio, fine/total aggregate ratio, and cementitious materials content. In all the mixtures, 8 % cement was replaced with silica fume. Compressive strength and modulus of elasticity were determined on cylindrical concrete specimens after 28 days of water curing. Electrochemical tests for determining corrosion penetration rate were conducted on reinforced concrete specimens with 25 mm cover thickness and exposed to 3 % NaCl solution after water curing for 28 days. The test results indicate that the type of coarse aggregate significantly affects the strength, modulus of elasticity, and steel-corrosion resistance of concrete. It was also noted that it is essential to control the quality of mortar while utilizing marginal quality aggregates.

Comparative Study of Corrosion Behaviour of Nickel and Gold Plated Carbon Steels Used as Ornamentals in Saline Environment

This study investigated the corrosion resistance of plated and unplated steels useful as ornamentals in saline environment. Nickel plating of carbon steel was done in watts solution for 25minutes with a current density of 3 Adm -3 at 60 o C. The nickel plated carbon steel was later gold plated for 20 minutes with a current density of 0.2 Adm -3 at 50 o C. The plated and unplated carbon steels were immersed in saline environment for 360 hours. Weight loss was taken every 24 hours in order to evaluate corrosion penetration rate (CPR). The results obtained showed that plated carbon steel generally offers a better corrosion resistance than the unplated one. Corrosion of ornamentals is equally gaining importance especially coated ornamentals. The use of nickel for ornamentals is gaining more prominence over silver rising due to its shiny surface and its cost. The use of nickel plated ornamentals just as gold plated ornamentals are being patronized will surely become common place due to affordability for the generality of people. However, the effects of everyday corrosive fluids from kitchen salt and low acidic media on the durability of the coatings need to be established. Carbon steel is the natural substrate used in orna- mental coatings .The results also showed that a small thickness of gold plated carbon steel exhibited better corrosion resis- tance in saline environment. More also, gold plated carbon steel is found to be more suitable and reliable candidate material than nickel plated carbon steel in this environment although with higher costs.

Electrodeposition and characterization of Ni–Co/SiC nanocomposite coatings

Ni–Co/SiC nanocomposite coatings were electrodeposited in a modified watt type of Ni–Co bath containing 20 nm SiC particles to be codeposited. Potentiodynamic polarization tests were conducted to study the effect of the SiC particulates on the electrodeposition of Ni and Co. Scanning electron microscopy was used to assess the morphology of the Ni–Co alloy and Ni–Co/SiC nanocomposite coatings. The distribution of the particulates in the matrix was considered by means of transmission electron microscopy. Applying nanomechanical testing instruments coupled to atomic force microscopy, mechanical properties of the alloy and composite coatings were studied and compared. The presence of 11 vol.% SiC in the Ni–Co matrix increased hardness more than 60%. The average depth of scratch in the mentioned composite coating was about 15% less than that of the Ni–Co alloy coating. The corrosion penetration rate (CPR) of the Ni–Co alloy coating in a 3.5 wt.% NaCl solution was more than 17 times greater than that of the Ni–Co/SiC coating with 30.5 vol.% SiC.

New Trends in Corrosion Analysis of Al-Sn Alloy Duplex System

The corrosion characterization of binary Al – Sn alloy systems has been statistically analyzed in the light of developed model equations. It was observed that the modeled corrosion penetration rate values generated using the developed model equations are in tandem with the experimental values.

Corrosion behavior of Zr–Cu–Ni–Al bulk metallic glasses in chloride medium

Polarization and passivation behavior of three Zr-based BMGs, i.e. Zr 58.3Al 14.6Ni 8.3Cu 18.8, Zr 58Al 16Ni 11Cu 15 and Zr 57.5Al 17.5Ni 13.8Cu 11.3 were investigated in 3% NaCl aqueous solution. Electrochemical investigations were carried out by potentiodynamic polarization method at room temperature. The corroded sample surfaces were examined using scanning electron microscope having energy dispersive spectroscopy (EDS) attachment. The results of the present investigation revealed that Zr 58Al 16Ni 11Cu 15 and Zr 57.5Al 17.5Ni 13.8Cu 11.3 BMGs having relatively larger supercooled liquid region (Δ T x ) and pitting overpotential ( η pit) values exhibit low corrosion current density ( i corr) and corrosion penetration rate (CPR) values.

Bio-corrosion study on zirconium-based bulk-metallic glasses

Bio-corrosion behaviors of Zr 55Al 10Cu 30Ni 5 and (Zr 55Al 10Cu 30Ni 5) 99Y 1 (at.%) BMGs in a physiologically relevant environment were investigated and compared to those of standard, crystalline biomaterials. The effect of 1 at.% yttrium addition on the corrosion resistance of the Zr 55Al 10Cu 30Ni 5 BMG was determined. Cyclic-anodic polarization tests were performed at 37 °C in a phosphate-buffered saline (PBS) electrolyte aerated with a 4 vol.% O 2/N 2 gas mixture. Surface morphologies after electrochemical studies were observed by the scanning-electron microscopy (SEM). Compositions of corrosion products were investigated by the energy dispersive X-ray (EDX) to identify the corrosion mechanism. It was found that (Zr 55Al 10Cu 30Ni 5) 99Y 1 BMGs exhibited a superior bio-corrosion resistance with a corrosion-penetration rate (CPR) comparable to those standard, crystalline biomaterials, while Zr 55Al 10Cu 30Ni 5 BMGs exhibited a lower bio-corrosion resistance. Possible mechanisms for the beneficial effect of the Y addition are proposed that the structure of the passive film was changed, and/or the formation of the passive film was accelerated.

Crevice Corrosion Penetration Rates of Alloy 22 in Chloride-Containing Waters

Abstract A possible waste package design for the disposal of high-level radioactive waste at the potential repository at Yucca Mountain, Nevada, may consist of an outer container made of Alloy 22 (...

The electrochemical evaluation of a Zr‐based bulk metallic glass in a phosphate‐buffered saline electrolyte

Bulk metallic glasses (BMGs) represent an emerging class of materials with an amorphous structure and a unique combination of properties. The objectives of this investigation were to define the electrochemical behavior of a specific Zr-based BMG alloy in a physiologically relevant environment and to compare these properties to standard, crystalline biomaterials as well as other Zr-based BMG compositions. Cyclic-anodic-polarization studies were conducted with a Zr52.5Cu17.9Ni14.6Al10.0Ti5.0 (at %) BMG in a phosphate-buffered saline electrolyte with a physiologically relevant oxygen content at 37 degrees C. The results were compared to three common, crystalline biomaterials: CoCrMo, 316L stainless steel, and Ti-6Al-4V. The BMG alloy was found to have a lower corrosion penetration rate (CPR), as compared to the 316L stainless steel, and an equivalent CPR, as compared to the CoCrMo and Ti-6Al-4V alloys. Furthermore, the BMG alloy demonstrated better localized corrosion resistance than the 316L stainless steel. However, the localized corrosion resistance of the BMG alloy was not as high as those of the CoCrMo and Ti-6Al-4V alloys in the tested environment. The excellent electrochemical properties demonstrated by the BMG alloy are combined with a low modulus and unparalleled strength. This unique combination of properties dramatically demonstrates the potential for amorphous alloys as a new generation of biomaterials.

On Calculating the Mean Corrosion Resistance and Total Thinning of Flat and Wire Metal Samples for Determining Atmospheric Corrosivity

Possible calculation errors are discussed as regards the environmental corrosivity monitoring based on the outdoor exposure and evaluation of the corrosion penetration rate of helical wire samples according to the ISO 9223 and 9226 International Standards.

Effect of Dissolved Ozone on Corrosion Behavior of Stainless Steels in Artificial Seawater

Abstract Corrosion resistance of austenitic stainless steels (SS) in artificial seawater containing 0.2 mg/L to 0.4 mg/L dissolved ozone (O3) was investigated. According to cyclic polarization data, types 304 SS (UNS S30400) and 316 SS (UNS S31600) were resistant to pit initiation after 8 weeks of exposure to ozonated artificial seawater. However, when crevices existed, crevice corrosion was more severe in ozonated vs aerated artificial seawater. Maximum crevice corrosion penetration rates of 8 mm/y and 5 mm/y (0.315 in./y and 0.197 in./y) were recorded for types 304 and 316 SS, respectively, in ozonated artificial seawater compared to only 0.4 mm/y to 0.5 mm/y (0.016 in./y to 0.020 in./y) under aerated conditions. Mixed-potential analysis of anodic and cathodic polarization predicted crevice corrosion rates for type 316 SS in excellent agreement with the immersion sample data. Highly alloyed nickel-, chromium-, molybdenum-, and nitrogen-bearing austenitic SS were resistant to crevice corrosion in aerated...

Galvanic corrosion between SiC monofilament and magnesium in NaCl, Na 2SO 4 and NaNO 3 solutions for application to metal-matrix composites

Galvanic corrosion of SiC monofilament (MF) coupled to pure Mg and ZE41A Mg alloy was studied using the potentiodynamic polarization technique in concert with the mixed-potential theory. Corrosion penetration rates of Mg were generally equal to 1 cm year −1 in de-aerated and oxygenated 3.15% NaCl, 0.5 M Na 2SO 4 and 0.5 M NaNO 3 solutions. Galvanic corrosion penetration rates varied from 0.046 to 7.3 cm year −1, depending on solution oxygenation and the exposed region of SiC MFs. NaF was very effective in reducing galvanic corrosion rates in de-aerated 0.5 M Na 2SO 4 and 0.5 M NaNO 3, modestly effective in oxygenated 0.5 M Na 2SO 4 and 0.5 M NaNO 3 and ineffective in 3.15% NaCl.

Electrochemical Protection of Zirconium in Oxidizing Hydrochloric Acid Solutions

Abstract An electrochemical protection technique using cathodic polarization to maintain zirconium below its critical repassivation potential was used to avoid pitting and stress corrosion cracking (SCC) in hydrochloric acid (HCl) containing ferric ions (Fe+3). Corrosion and pit penetration rates are reported for pickled, abraded, and as-received surface conditions in 10, 20, and 37% HCl containing 50, 100, or 500 ppm Fe+3 at temperatures to boiling. The pickled surface was the least susceptible to pitting in the 64 day tests. Electrochemical protection is then evaluated for total immersion, partial immersion, U-bend, and constant strain rate tensile tests. Protection is effective in eliminating pitting and SCC in 10 and 20% HCl containing Fe+3.

Test Methods to Predict Long-Term Corrosion of Container Materials in Repositories

AbstractMCC test methods in support of basalt, salt and tuff repositories are described. The methods consist of three general corrosion tests for basalt, two general corrosion tests and three stress corrosion tests for salt, and two general corrosion tests for tuff. The tests encompass the various conditions that are expected in the different repositories. A summary is provided of experimental activities of the MCC, and detailed results of MCC 105.1 Test Method for Long Term General Corrosion in a Basalt Repository (Static System) for standardized, benchmark conditions are presented. A summary of the statistical treatment of data is provided with examples of confidence intervals and the dependence on number of test vessels. The total relative standard deviation for the mean corrosion penetration rate was 11.4% for a mean corrosion penetration rate of 0.0244 mm/yr for 120 d tests at 100°C.