Weight Loss Corrosion Tests Research Articles

Effect of Temperature on Corrosion Behavior and Mechanism of S135 and G105 Steels in CO2/H2S Coexisting System

The corrosive environment of oilfield condensate water was simulated at different temperatures with CO2/H2S. Weight-loss corrosion tests were conducted on S135 and G105 steels at different temperatures. The corrosion rates of the S135 and G105 were measured at room temperature, 100 °C and 180 °C. The phase structure of the corrosion products and the corrosion morphologies of the samples were characterized. The results show that the corrosion rates of the S135 and G105 increased at first and then decreased with the increase in temperature. The corrosion rates peaked at 100 °C, reaching 0.8463 mm/y and 0.8500 mm/y, respectively. CO2 was the main controlling factor in the corrosion. The corrosion products were FeS and FeCO3. The corrosion rate at room temperature was lower than that at 100 °C. The corrosion rate at the temperature of 180 °C was the lowest. The corrosion rates of the S135 and G105 were 0.2291 mm/y and 0.2309 mm/y, respectively. CO2 was not the main controlling factor in the corrosion. The corrosion product was FeS. High temperatures aggravated the carbon-steel corrosion further in the environment with the high concentration of CO2 and a loose corrosion-product film formed. The dense and uniform FeS corrosives formed and attached to the surface of the substrate, and inhibited corrosion. Dense and uniform FeS products formed on the surface of the steel with the increase in temperature. A small amount of H2S inhibited the progress of the corrosion.

Influence of In-situ induction heated friction stir welding on tensile, microhardness, corrosion resistance and microstructural properties of martensitic steel

Induction Heated Friction Stir Welding (IH-FSW) was conducted using two varying parameters and two fixed parameters. The microstructure evaluation shows that the nugget zone’s grain size is smaller while comparing with the parent metal. Due to dynamic recrystallization during the induction heated friction stir welding, well-equiaxed grains were found in the nugget zone. The microhardness test reveals that the welded region have improved hardness than the parent metal; the high hardness was attained in the heat-affected zone. The 3 h and 24 h of weight-loss corrosion test methods were conducted using the coefficient of 0.5 M H2SO4, showing that the stir zone’s corrosion resistance is better than the parent material. The given parameter combinations obtain the best results, tool rotation of 1250 rpm, welding speed of 45 mm min−1, shoulder penetration of 0.50 mm and induction heat input of 441.8 °C at 50 W.

Tribological and Corrosion analysis of Co-20Al-GNSA composites produced through powder metallurgy process

In this study,Co-20Al-GNSA metal matrix composites were produced using mechanical alloying process. The Co-20Al-GNSA composites were mixed using a high-energy ball mill at a constant speed of 350 rpm for 2hours. The composite powders were then characterized for their morphological study using Scanning Electron Microscope. The composite powders are then compressed and sintered at 500MPa and 700°C respectively. The density and compressive strength of the composite materials shows decrement values whereas the wear resistance of the composite materials has increased considerably. The mechanism of wear was identified as abrasive wear. The electrochemical corrosion test also reveals that the Co-20Al-10GNSA composites have better corrosion resistance. The weight-loss corrosion test also shows that the composites with 10GNSA content have better corrosion resistance.

Anisotropy in Mechanical Properties and Corrosion of X-52 Pipeline Steel at Different Pipe Angles

Non-uniform corrosion and cracking could occur at different pipe angles (different clocks) on oil and gas transmission pipelines. While this could be due to different environmental conditions surrounding the pipeline or nonuniformity in microstructure, mechanical and corrosion properties at different pipe angles. This study investigates corrosion and mechanical properties of X-52 pipeline steel at different pipe angles. In this regard, microscopic characterization, weight loss corrosion tests, electrochemical corrosion tests, and also mechanical characterizations tests (hardness, tensile and fracture toughness) were performed. Results showed that corrosion and mechanical properties of the X-52 pipeline steel was not uniform at different pipe angles and 180 degree (6 o’clock) position had the most corrosion rate and fracture toughness. Nonuniformity in grain orientations and microstructure of pipeline steel is considered to be the reason for anisotropy observed in corrosion and mechanical properties.

Studi Penambahan Inhibitor Organik Ekstrak Daun Bawang Tiwai (Eleutherine americana Merr.) pada Baja API 5L dalam Lingkungan 3,5% NaCl

One that can be used as an organic inhibitor is bawang tiwai leaves extract. This study used 3.5% NaCl as corrosive media with inhibitor concentration of bawang tiwai leaves extract from 0 ppm to 500 ppm and immersion time from 10 days up to 30 days. The efficiency of inhibition was measured using a weight loss corrosion test, while the corrosion rate was obtained from polarization measurements. The FTIR test results show that the extract contains flavonoid compounds that act as antioxidants and inhibit corrosion. Inhibitory efficiency achieved up to 95.4545% for the addition of 300 ppm inhibitor and 20 days of immersion time. This inhibitory behavior is also supported by polarization measurements where the lowest corrosion rate of 0.00128 mm/year is obtained at the same concentration and immersion time.

Wear and Corrosion of Wrought A6061 Aluminium Alloy in DOT3 Brake Fluid

The twofold impact of wear and corrosion on wrought A6061 alloy in hydraulic DOT3 brake fluid environment was studied. The wear studies were performed on the samples using a developed wear-jig. Weight loss corrosion test method was used to determine the corrosion rate of the wrought A6061 alloy samples immersed in the brake fluid for a total of 1680 hours. From the results of wear tests carried out on the A6061 alloy sample with brake oil, the highest wear value of 5.24x10-7 mg/mm2/cycle (approx.) was obtained from 6 N (approx) force after 130 minutes. The wrought A6061 alloy material demonstrated the highest corrosion rates nearly 3.0 x10-2 mg/mm2/yr within the early 168 hours of immersion in brake fluid. The result is practically lower than the corrosion rate of cast specimen in DOT3 brake oil or some other alloys immersed in other corrosive media that were previously reported in the literature. The results show that small amount of chemical corrosion is sufficient to cause and accelerate mechanical wear of the material in usage.

Studies of ZA-27 / Red Mud Metal Matrix Composites with respect to Corrosion Properties

Conventional monolithic materials have boundaries in achieving good properties like strength, stiffness, toughness and density. To overcome these weaknesses and to meet the ever increasing demand of modern day technology, composites are most auspicious materials of recent interest. Metal matrix composites are most successful materials used for recent works in the industry. Metal matrix composites own significantly improved properties including high tensile strength, toughness, hardness, low density and good wear resistance compared to alloys or any other metal. They also exhibit increased corrosion resistance. There has been an increasing demand in composites containing low density and low cost reinforcements. In this studies popular alloy of nineties ZA-27 is chosen as matrix and red mud particulates which is obtained as a waste in the aluminium manufacturing industries is selected as reinforcement. Liquid melt metallurgy technique using vortex method is chosen for the manufacture of metal matrix composites. Reinforcement content added to matrix was 2 percent 4 percent and 6 percent. Matrix alloy was also casted in the same way for comparison. Microstructures of the composites and matrix alloy are taken by scanning electron microscope technique after machining. Static weight loss corrosion test and potentiodynamic polarization techniques test using potentiostat were conducted in different concentrations of sodium chloride solutions. Specimens for the tests mentioned already are machined from the castings according to ASTM standards. Corrosion rates were calculated after knowing the weight loss in static weight loss corrosion test. Elico company make Potentiostat / Galvanostat model CL95 was used for the determination of corrosion current and corrosion rate. In all the tests the corrosion current was found to decrease from matrix alloy to 6 percent composite. Corrosion rate was also to be decreased from matrix alloy to 6 percent composite. Hence metal matrix composites made up of ZA-27 as matrix and red mud as reinforcement are more suitable for marine applications and automobile applications in place of matrix alloy.

The influence of temperature on the inhibition of carbon steel corrosion in acidic lignin

Purpose– This paper aims to investigate the influence of temperature and lignin concentration on the inhibition of carbon steel corrosion in 1 M HCl.Design/methodology/approach– Weight loss corrosion tests were performed at different temperatures in the range of 30-70°C (303-343 K).Findings– It was found that the corrosion inhibition efficiency (IE) of lignin on the carbon steel decreased when the temperature was increased from 60 to 70°C. However, at lower temperatures ranging from 30 to 50°C, the IE improved, due to occurrence of lignin adsorption on the surface of metal specimens. The IE was higher with increasing lignin concentration, thus reducing the weight loss of the carbon steel. The adsorption phenomenon involved exothermic processes because the value of enthalpy of adsorption (ΔH°ads) < 0 and Gibbs free energy of adsorption (ΔG°ads) were less negative with increase in temperature. The entropy of adsorption (ΔS°ads) had negative values, representing the decrease in disorder of adsorption. The adsorption of lignin on the carbon steel surface in 1 M HCl was comprehensive, as deduced from kinetic and thermodynamic parameters. However, physisorption was the major contributor in the inhibition mechanism. The inhibitive features of carbon steel surfaces showed less damage once the steel was treated in lignin, as evident from macroscopy images.Practical implications– The use of lignin as an acid corrosion inhibitor at high temperature is practical in metal surface treatment process.Social implications– The use of organic compounds gives an advantage to the environment, universal health and save cost, as the compounds can be found in nature.Originality/value– Lignin can act as a flexible corrosion inhibitor within the temperature range of 30-70°C in 1 M HCl because it exhibits comprehensive adsorption (i.e. a combination of both physisorption and chemisorption) at specific concentrations.

Corrosion Properties and Impact Toughness of 2205 Duplex Stainless Steel after TIG Welding*

Abstract Application fields for duplex stainless steels are drastically increasing. Industries producing and operating petrochemical process equipment, pipelines, bridges, pressure vessels, heat exchangers, rotors, and sea-water systems have a high demand for these steels. In this study, UNS S32205 duplex stainless steel plates of 3 × 40 × 145 mm were TIG welded with welding wires of W22 9 3 NL (2209). The main aim was to investigate the effects of various amounts of magnetic δ-ferrite and other important phases or intermetallic compounds that are formed during and after welding. The phase quantities differing by the welding conditions and argon shielding gas mixtures containing 0, 1, 3, 6, and 9 vol.-% N2 are studied. The investigations included Charpy V-notch impact tests, weight loss corrosion tests, and microstructural analyses according to ASTM A 923 and magnetic δ-ferrite measurements according to EN ISO 17655, and EN ISO 8249 as well as image analyses according to ASTM E-562, ASTM E 1245 for a comparision of the effect of the amounts of all phases. The differences with respect to the welding parameters were also identified.

Corrosion Characterization of Al6061/Red Mud Metal Matrix Composites

Metal matrix composites are heterogeneous systems containing matrix and reinforcement. Their physical and mechanical properties can be tailored according to requirement. They are used in automobile, aircraft and marine industries because of their increased corrosion resistance. In this paper weight loss corrosion test, open circuit potential test and potentiostat test are conducted on AL6061/ Red Mud metal matrix composites in different concentrated neutral chloride solutions like sodium chloride solutions. Composites are prepared by liquid melt metallurgy technique using vortex method. Composites containing 2, 4 and 6 percent of red mud are prepared according to ASTM standards. Specimens are machined and made ready by standard metallographic methods. Weight loss corrosion studies, open circuit potential studies and potentiostat studies, are carried out in 0.035, 0.35 and 3.5% solutions of sodium chloride. The corrosion rate decreases with increase in the exposure time for all specimens in all corrodents in all the methods of testing. Corrosion rate also decreases with the increase in reinforcement content of the composites. Hence the composites can be used for the manufacture of the equipments used in marine environment so that they lost long.

In Situ Synchrotron X-Ray Diffraction Studies of CO2Corrosion of Carbon Steel with Scale Inhibitors ATMPA and PEI at 80°C

In situ synchrotron x-ray diffraction was used to investigate experimentally the effect of two common scale inhibitors, amino trimethylene phosphonic acid (ATMPA) and polyethyle-neimine (PEI), on the corrosion rate and protective scale formation process during carbon dioxide (CO2) corrosion of carbon steel. These experiments were performed under mild anodic polarization in sodium chloride (NaCl) solutions at ~1 bar CO2, 80°C, and pH 6.5, such that a protective scale would form readily in the absence of any organic scale inhibitors. These results were compared with longer-term open-circuit weight-loss corrosion tests in similar conditions but at up to 30 bar CO2. The scale inhibitors had complex, concentration-dependent effects but in general had a very significant inhibitory effect on the nucleation and growth of siderite (FeCO3), and as a consequence resulted in an increased corrosion rate. The results of pulsed galvanostatic experiments were consistent with the scale inhibitors acting by adsorption onto...

Corrosion Testing of Weldments

Abstract Weldments sometimes corrode preferentially in the weld metal itself or in the heat affected areas of the parent metal. The localized nature of the attack limits the usefulness of standard weight loss corrosion tests. Techniques for overcoming this limitation are discussed. The influence of specimen geometry and surface finish are dealt with as well as a variety of destructive and nondestructive methods for evaluating a corroded weldment. The advantages and limitations of the various ASTM intergranular tests for austenitic stainless, ferritic stainless, and nickel base alloys are reviewed. Guidelines for evaluating weldment corrosion are given, although it is recognized that there is no single best procedure for all situations. The use of sensitization treatments to simulate welding is discussed.

Corrosion of Type 430 Stainless Steel: Effects of Mo-Pd and Other Addition Pairs

Abstract Continuing previous work on the effects of single additions, anodic and cathodic polarization measurements were performed at room temperature in N H2SO4, with and without 0.5N NaCl, on Type 430 ferritic stainless steels containing addition pairs of Mo, V or W with each of Pd, Ge or Re. Weight loss corrosion tests were also carried out in the solutions used in the polarization measurements, in N HCl, in N FeCl3, and in H2SO4 over a range of temperatures and concentrations. Except in sulfuric acid, in which the Pd bearing alloys showed extremely good resistance, corrosion behavior of alloys containing the various addition pairs was generally inferior to that of the corresponding alloy containing Mo, V or W only. Of the Pd bearing alloys, the Mo-Pd combination showed the best corrosion behavior in H2SO4 at the lower acid concentrations. As indicated by potential measurements, in steels having the nominal additions 3% Mo-1/2% Pd and 2% Mo-1% Pd, comparatively large regions of spontaneous passivity we...

Passivity of Titanium in Hydrochloric Acid Solutions

Electrode potential measurements and weight loss corrosion tests indicate that air or low concentrations of certain dissolved metals passivate titanium in hydrochloric acid solutions and that passivity is accompanied by more noble electrode potentials. Air passivates titanium in acid up to 3N. Two hundred mg/l Cu++ is effective in 10N hydrochloric acid and 2 mg Cu++ passivate titanium in 5N acid. The more noble electrode potentials indicate that a reaction involving oxygen, metal ions, or ions containing oxygen takes place at the passive surface but there is no visible deposit on, or change in, the appearance of the surface except for an occasional slight tarnish. Titanium in contact with small volumes of stagnant 10N hydrochloric acid containing 200 mg/1 Cu++ loses its passivity after a period of time. This time interval seems to be directly proportional to the ratio of solution volume to specimen area and the loss of passivity is attributed to the presence of atomic hydrogen.