Papers by Keyword: Corrosion Rate

Abstract: SS316L material exhibits superior corrosion resistance. The two grade compositions, comprising nickel and molybdenum, enable the alloy to resist acids and chlorides without degradation. Due to its exceptional corrosion resistance, both metals are among the few classified as "marine grade stainless steels." Gas Tungsten Arc Welding (GTAW) is executed to guarantee sufficient corrosion resistance during installation. This study analyzes the outcomes of welding ER316LSi as a filler material with SS316L base metal, focusing on microstructure, EDAX analysis, and corrosion rate. This study did not perform hardness testing. This study will indicate welding variables for future research on specific applications, utilizing various weld blades and current parameters. Corrosion testing, encompassing Tafel and Electrochemical Impedance Spectroscopy, indicates that the SS316LSi weld metal will yield a higher degree of ferrite development in the weld region. The welding temperature significantly influences the ferrite structures. The corrosion rates for each electrolyte solution are as follows: for the seawater electrolyte solution, a current of 110A yields a rate of 8.39857 x 10^-6 mpy, 120A results in 7.09315 x 10^-6 mpy, and 130A produces a rate of 7.85427 x 10^-6 mpy. The MgCl₂ electrolyte solution exhibits a concentration of 110A = 7.2195 × 10^-6 mpy, a current of 120A = 7.2156 × 10^-6 mpy, and a current of 130A = 7.1406 × 10^-6 mpy. The corrosion resistance at a current of 120 amperes is greater in seawater conditions than at a current of 130 amperes in MgCl2 solutions. The corrosion rate and reductions in Fe, Mo, Cr, and Mn following 14 days of immersion testing in sewage and MgCl2 are the reasons that low-heat-input or solid-phase bonding techniques can significantly enhance pitting resistance compromised by welding.

Abstract: This study investigates the corrosion resistance of Stainless Steel 201 through varying surface treatments and testing in a 3.5 wt% NaCl solution, mimicking seawater conditions. Given its prevalent use in industries like oil, Stainless Steel 201's resistance to pitting corrosion is crucial, primarily when used in pipes. The research employs electrochemical techniques, specifically Cyclic Voltammetry and Immersion, to treat the material's surface. The surface treatment using citrict acid (C₆H₈O₇) varying the concentration of 1, 1.5, and 2 M. Corrosion tests utilize open circuit potential, anodic polarization patterns, and characterization via optical microscopy and SEM-EDS. Results indicate that the material subjected to a Cyclic Voltammetry treatment with 2M citric acid exhibited the lowest corrosion rate at 0.001243 mmpy, with 21 instances of pitting corrosion. Conversely, untreated Stainless Steel 201 showed a higher corrosion rate of 0.006177 mmpy and 87 instances of pitting corrosion. This underscores the significant improvement in corrosion resistance achieved through the specified surface treatment, highlighting its potential value for enhancing Stainless Steel 201's longevity and performance in corrosive environments. Keywords: Stainless Steel 201, Cyclic Voltammetry, Immersion, Open Circuit Potential (OCP), Anodic polarization Patterns, Corrosion Rate, Pitting Corrosion.

Abstract: Stainless steel 316L (SS316L) is widely used for applications that require corrosion resistance, especially in acidic environments. Despite its importance, the corrosion mechanism of SS316L in concentrated sulfuric acid at room temperature has not been sufficiently studied. In this research, the corrosion behavior of welded and bent SS316L specimens was investigated by varying the surface roughness, achieved by ground using 120-grit abrasive paper and polished until it mirror-like. The specimens were compared through immersion tests for three days at a temperature of 25°C. The chemical composition was analyzed using optical emission spectroscopy (OES), and the microstructure was observed using optical and scanning electron microscopy (SEM). Experimental tests and analysis showed that surface roughness increased the corrosion rate. Increasing the sulfuric acid concentration also increased the corrosion rate, but at a concentration of 50% wt, no corrosion occurred due to the stability of the passive layer.

Abstract: Steel construction is one of the main constructions for building and bridge structures because it has great tensile strength. However the main drawback is its resistance to corrosive environments which makes steel very corrosion prone. So that the use of steel construction must pay attention to the corrosion rate in the environment of use. So we try to do research on the level of corrosion rates in the tropics. This study aims to determine the atmospheric corrosion rate on steel plates in the city of Palu which is in the tropical region and the effect of the angle of installation of the steel plates. In this study there were 27 specimens and each variation of specimens totaled 9 consisting of PL45, PL90 and PL180 plates with a size of 160x80x5 mm. The results showed that the highest corrosion rate occurred in the first month and at an angle of 180⁰ with a corrosion rate value of 2.03 mpy and the lowest corrosion rate occurred in the third month and at an angle of 90⁰ with a corrosion rate value of 1.01 mpy. From this study it can be concluded that the corrosion rate that occurs in Palu City in the tropics is still in the very slow category for all test specimens based on corrosion engineering books.

Abstract: The advent of innovative, reasonably priced additive manufacturing techniques has been facilitated by the industry 4.0 era. This study aims to characterize the ER70S-6 wire arc additive manufacturing (WAAM) layer in metal inert gas (MIG) as a result of controlled process speed, electrode type, voltage, and weld current using a three-axis automated motion framework. The study approach begins with the design and building of an automated MIG welding motion system, which includes component manufacture, assembly, calibration, and motion path testing. The specified settings modify the speed of the weld probe motion in response to manual welding parameter adjustments. The investigation continues with the characterization of single to four-layers of WAAM to know the corrosion rate, microstructure, and the Vickers hardness. Corrosion testing results showed that the single-layer of WAAM had the lowest corrosion rate, as well as the highest hardness. Whereas the four-layer had the highest corrosion rate and the lowest hardness.

Abstract: In this investigation, the resistance of brass material to stress corrosion cracking (SCC) in a chloride solution was assessed through adjustments in temperature (25°C, 35°C, and 45°C) and bending angles of the brass material (1.0 wt%, 2.0 wt%, and 3.5 wt%). The chosen solution closely resembles saltwater, making it suitable for testing, especially considering the widespread use of brass materials in various industrial sectors, particularly shipping. Stress corrosion cracking tends to impact brass materials under heavy loading. The primary objective of this study is to characterize the corrosion rate of brass materials. The method involved a bending test with angle variations of 180°, 90°, and 0°. Corrosion assessment utilized the Open Circuit Potential method, Anodic Polarization Tafel, and a digital microscope for the material's microstructure properties. According to the findings, brass material exhibits the lowest corrosion rate (10 x 10^-6 mmpy) at a temperature of 25°C distilled water and an angle variation of 0°. Conversely, the corrosion rate increases with variations in bending angle, temperature, and the concentration of NaCl solution, as evidenced by the corrosion rate of 28.035 x 10^-5 mmpy with an angle variation of 180°, to a corrosive solution of NaCl 3.5 wt% at a temperature of 45°C.

Abstract: Corrosion inhibitors are substances that protect metal surfaces by forming a protective film to prevent metallic materials in contact with corrosive environments. Inhibitors are created with capability to adsorb onto the metal surface, creating a barrier film, or neutralizing the detrimental effects of corrosive substances. Their performance are evaluated based on the ability in reducing corrosion rate. Traditionally, corrosion inhibitors made of chemical synthetic compounds. But as synthetic inhibitors have environmental impact, researchers are starting to explore compound alternatives. Currently, inhibitor technologies have demonstrated a remarkable growth in performance marked by the discovery of new types of inhibitors. Ongoing research are focusing on self-healing inhibitor, eco-friendly inhibitor, and nanostructured compounds inhibitors. This paper will comprehensively address the current challenges of advanced corrosion inhibitors. From the investigation, it has been noticed that application of innovative technologies has led to a transformative impact in producing with significant enhancement in their overall performance capabilities.

Abstract: Metal is widely used in various industrial fields such as transportation because of its physical and mechanical strength. However, during its utilization, metal materials are often damaged by corrosion due to chemical reactions between the metal surface and the surrounding environment. Coating is one way to prevent corrosion by isolating metal surfaces from the environment. Conventional anti-corrosion coatings generally use chromate and phosphate-based materials. However, this material has been banned in some countries because it is toxic to the environment. Meanwhile, other methods with the addition of more active metals such as magnesium are considered unaffordable. Therefore, the researchers developed alternative materials that are environmentally friendly and reduce costs by using metal oxide-based materials such as Silicon dioxide (SiO₂). The advantage of SiO₂ is that it is chemically stable and harmless. SiO₂ modification produces hydrophobic properties which increase corrosion resistance. One of the methods to make SiO₂ is sol-gel method. The advantages of sol-gel method are simple, affordable, capable of forming a film for attaching chemical properties, flexible for incorporation with other compounds and the coating can be applied in several ways, such as dip coating, spray coating, electrophoretic deposition (EPD), etc. As an anti-corrosion coating, products can be tested for their resistance by analyzing the corrosion rate. This paper reviews silica-based metal coatings as anti-corrosion. The scope of the discussion in this paper is the mechanism, fabrication route, application technique, characterization, and analysis of anti-corrosion ability by studying the corrosion rate of anti-corrosion silica-based coating products for metal substrates.

Abstract: Corrosion has severe consequences for the integrity of pipelines used in the petroleum industry. Modelling and optimising the parameters of a circulating fluid are two of the numerous methods for combating corrosion. The objective of this study was to develop a multiphase flow simulation model for estimating the corrosion rate of oil and gas pipelines, considering the erosional effect. In addition to carbon dioxide (CO₂) and hydrogen sulphide (H₂S) corrosion, the present model also takes into account the impacts of chloride concentrations. The current model evaluates and reflects a comprehensive understanding of corrosion in a saline environment, making it readily applicable for estimating corrosion rates for industrial applications. The model's results indicate a prediction accuracy of about 85%. Field data gathered under a broad range of environmental conditions confirms the model's prediction accuracy. The predictions from the present model are in good agreement with the field data. In addition, the present model was found to be more effective than the model created by Dewaard and Milliam. This research is likely to have widespread applications in the oil and gas industry for predicting more accurate corrosion rates.

Abstract: A comparative study of the structure and properties of two biodegradable Fe – 27Mn and Fe – 27Mn – C alloys for biomedical use after equal channel angular pressing (ECAP) has been carried out. It is noted that addition of carbon in the alloy leads to a change in the mechanism of plastic deformation from the formation of martensite to deformation twinning in austenite. ECAP improves the strength characteristics of the alloys under study and the corrosion rate by refining the structure and increasing the dislocation density. The presence of a partially twinned structure in the Fe – 27Mn – C alloy results in a lower corrosion rate despite a stronger refinement of the alloy structure after ECAP.