Corrosion of Carbon Steel and alloy Steel: effect of humidity and hydrochloric acid (original) (raw)
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Comparative Study and Analysis of Carbon Steel Corrosion in co2 Saturated Environment
African Journal of Engineering and Environment Research, Volume 2 of 1, January, 2021
Carbon steel is arguably one of the most efficient, reliable and safer kind of steel used in petroleum and gas industry for production, distribution and transmission of products. Acetic acid (HAc), is also one of the impurities in oil and gas during transportation from the well sites to the refineries. It is formed in the formation water, which also present in oil and gas production and transportation processes. Acetic acid aids corrosion in pipelines and as a result causes environmental degradation. It has been observed that high concentration of HAc increases the rate of corrosion of carbon steel in CO2 environment. Corrosion slows down production of oil and gas and thereby reduces revenue. In this work, a comparative study and analysis of carbon steel corrosion in the presence of HAc was carried out at 25 o C and 80 o C in CO2 saturated environment. Weight loss and surface analysis methods (XRD, EDX and SEM) were used to characterize the corrosion layers of the carbon steel samples at different conditions. The weight loss results show that the corrosion rate increased initially with the increase in the concentration of HAc and attained a maximum, and then gradually decreased. At 25 o C with 500ppm of HAc, the corrosion rate is 1.35 mm/yr, and 1.80 mm/yr when 1000ppm of HAc was added to the solution. At 80 o C and 500ppm HAc, the corrosion rate was 1.80 mm/yr and 2.70 mm/yr with 1000ppm of HAc. A further increase was observed at 3.45 mm/yr when 2500ppm of HAc was added to the system. This increase in corrosion rate is attributed to increase in temperature as increased temperature increases the rate of all reactions. The XRD analysis confirmed that the iron is formed in the absence of HAc while siderite (FeCO3), which is an ore of iron is observed on the materials with HAc. The SEM and EDX results confirmed that a fairly dense material of FeCO3 was formed in the absence of HAc and the layers became porous on addition of HAc to the solution.
EFFECT OF HOT CORROSION ON BOILERS PIPES IN NORTH BAGHDAD ELECTRIC POWER PLANT STATION
The high temperature external corrosion of boiler pipes was evaluated using weight loss technique. Samples of low carbon steel were supplied from north of Baghdad thermal station and used in current study. Locally supplied fuel ash was used as corrosion environment. Corrosion rates were determined as a function of time in the absence and presence of fuel ash. The results showed that the corrosion of boiler steel pipes was higher in the presence of fuel ash. Scanning electron microscope was also used to study the morphology of surface.
Corrosion behaviour of mild and high carbon steels in various acidic media
The corrosion behaviour of mild steel and high carbon steel in various concentrations of nitric acid (HNO 3 ), hydrochloric acid (HCl), and perchloric acid (HClO 4 ), has been studied. Specimens were exposed in the acidic media for seven days and corrosion rates evaluated, using the weight loss method. It was observed that nitric acid environment was most corrosive to both steels because of its oxidizing nature, followed by perchloric acid, and lastly, hydrochloric acid. The corrodent concentration and exposure time affected the corrosion of the metals. The rate of metal dissolution increased with increasing concentration of the corrosion media and exposure time. Corrosion rates of mild steel in all the acidic media studied were found to be higher than that of high carbon steel. This could be attributed to the fact that the carbon content in itself has little if any effect on general corrosion resistance of steels.
Comparative Analysis of Corrosion Rate of Low Carbon Steel in Acidic Environment
Nigerian Journal of Engineering Science Research, 2021
Low carbon steels (0.002-0.25%) account for a large proportion of the total output of steel. They are the most vital alloys used in petroleum and petrochemical industries since they account for over 98% of the construction materials. The wide application of low-carbon steel ranges from chemical, oil gas storage tanks and transportation pipelines are due to its moderate strength, good weld-ability and formability. However, the use of low carbon steel as construction material in industrial sectors has become a great challenge due to the effect of corrosion. This research work is focused on the comparative analysis of corrosion rate of low carbon steel in acidic environment. A low carbon steel of 0.145 weight percentage of carbon bought from a local market in Nigeria was used for this research work. The purchased low carbon steel sample was machined using lathe machine into cylindrical pieces of diameter of 25 mm and length of 60 mm and divided into four samples (Sample A, Sample B, Sample C, and Sample D). Four plastic bowls were filled with in traoxosulphate (vi) acid, hydrochloric acid, trioxosulphate (iv) acid, and ethanoic acid were used as acidic environment. The various steel samples were weighed with an analytical weighing balance before and after being immersed in the acidic environment in an interval of ten (10) days. The results obtained revealed that corrosion rate was comparatively high in the first twenty (20) days, and this was followed by continuous decrease in the corrosion rate of all the samples. However, the corrosion rate of the samples become partially uniform after thirty (30) days and the pattern remain the same for the remaining twenty (day 30-day 40) days and finally decreased gradually with subsequent increase in exposed acidic environment. More so, it was observed that samples soaked in the acidic solution of tetraoxosulphate (vi) acid shows a more aggressive corrosion rate as Manuscript History
Atmospheric Corrosion of Carbon Steel and Corresponding Corrosion Products
ANNALS OF THE ORADEA UNIVERSITY. Fascicle of Management and Technological Engineering., 2010
The atmospheric corrosion of carbon steel is presented on base of the literature data study. In paper are given the principles of the corrosion steel in atmosphere, the principal variables that influence the corrosion rate, including the humidity, temperature and presence of the pollutants, and also the possible corrosion products formed on the carbon steel surface. 1.INTRODUCTION One of the most frequently corrosion type is the atmospheric corrosion. This has been reported to account for more failures in terms of cost and tonnage than any other type. About 80% from all degradations produced by corrosion in the metallic constructions are due to the atmospheric corrosion. The atmospheric conditions for corrosion are very complex and the corrosion rates vary in function of geographic zone, of season and daily time. The complexity of the atmosphere, as corrosion environment, results from atmosphere composition and from presence of some factors as pollutants, temperature, humidity, wind speed and direction, etc. [1]. These variables make meaningful results from laboratory experiments very difficult to obtain. The atmospheric corrosion is conveniently classified in three [2, 3] types: (1) dry oxidation, (2) damp corrosion and (3) wet corrosion. Dry oxidation takes place in the atmosphere with all metals that have a negative free energy of oxide formation. For metals forming non-porous oxides, the films rapidly reach a limiting thickness since ion diffusion through the oxide lattice is extremely slow at ambient temperatures, and at the limiting thickness, the oxide films on metals are invisible. For certain metals and alloys, these films confer remarkable protection on the substrate, e.g. stainless steel, titanium and chromium. The damp and wet atmospheric corrosion are characterised by the presence of a thin, invisible film of electrolyte solution on the metal surface (damp type) or by visible deposits of dew, rain, sea-spray etc. (wet type). In these categories may be placed the rusting of iron and steel, 'white rusting' of zinc (wet type) and the formation of patina on copper and its alloys (both types). The corrosion products may be soluble or insoluble. Usually, those insoluble reduce the corrosion rate by isolating the substrate from the corrosive environment. Less commonly, they may stimulate corrosion by offering little physical protection while retaining moisture in contact with the metal surface for long periods. The soluble products may increase corrosion rates. The severity of atmospheric corrosion depends on the environment type [4, 5]: rural, urban, industrial, marine and combined. The rural atmosphere generally the least corrosive and normally does not contains chemical pollutants. The principal corrosive agents are moisture, oxygen and carbon dioxide. The urban atmosphere is similar to the rural type in that there is little industrial activity. Additional contaminants are of the SO x and NO x variety, from motor vehicle and domestic fuel emissions.
The effects of coastal environment and flue gases are major problems on the operations of industrial machines and the situation is not different at Takoradi Thermal Power Station (TTPS). It was observed that the relative humidity in the area coupled with the production of chloride ions and the formation of ammonium nitrate and ferric hydroxide are the major causes of corrosion at the plant. This paper sought to identify the causes of corrosion and their effects on machinery at TTPS. The major occurrence of corrosion was found to be pitting corrosion and induced stress corrosion cracking occurring on the tanks, pipes and tubes in the Heat Recovery Steam Generator (HRSG). Consequently, this has led to the leaking of pipes, tanks and loss of production. The use of epoxy paint on the pipes and tanks will go along way to reduce the effects.
Determination the Corrosion Rate of Carbon Steel (0.4%C) Due to Thermal Cycling, Oil Cooled
2021
The effect of thermal cycling was carried out on steel bars (0.4 C %). A single run was performed at a lower temperature of 32℃ and an upper temperature of 500℃ cooled in water, seawater (previous results) and oil (new results). For several numbers of cycles up to 30 cycles for an accurate determination of heating and cooling times. The effect of thermal cycling on the corrosion rate was evaluated. The effect of thermal cycling on the following properties was evaluated the corrosion rate. The comparison between the effect of thermal cycling on carbon steel (0.4 C %) seawater and water-cooled (previous results as shown in references [1, 2]) and the effect of thermal cycling on carbon steel (0.4 C %) water-cooled (new results) has been studied. From the obtained test results (previous and in this paper, it was found that: the type of corrosion is uniform attack; corrosion rate of the first stage gradually increases with the number of thermal cycling up to 15 cycles, then it takes stea...
Structures, 2020
The objective of the paper was to experimentally examine the effects of corrosion wear on the chemical and mechanical properties of structural steels. Naturally-progressed corrosion testing on structural steel specimens was conducted during a period of 12 months. Three types of structural steels were tested: mild steel (grade A), AH32 steel, and DH32 steel. Different conditions of the corrosive environment were applied with three dry or water-immersed conditions, namely air (dry), freshwater immersion and seawater immersion, and with three temperatures, namely room temperature (18 o C), 0 o C, and-10 o C. The chemical and mechanical properties of structural steels were measured before and after the corrosion testing. Based on the test results, the characteristics of corrosion progression rate for structural steels were studied and reported in a separate paper [21,
Effect of Thermal Cycling on Corrosion Rate of Carbon Steel (0.4%C), Water Cooled
2020
The effect of thermal cycling was carried out on steel bars (0.4 %C). A single run was performed at a lower temperature of 320C and an upper temperature of 5000C cooled in water and seawater. For several numbers of cycles up to 30 cycles for an accurate determination of heating and cooling times. The effect of thermal cycling on the corrosion rate was evaluated. The effect of thermal cycling on the following properties was evaluated the corrosion rate. The comparison between the effect of thermal cycling on carbon steel (0.4% C) seawater cooled (previous results, sea-water cooled [1]) and the effect of thermal cycling on carbon steel (0.4 C %) (in this manuscript, water-cooled) has been studied. From the obtained test results (previous and in this paper, it was found that the type of corrosion is uniform, the corrosion rate of the first stage gradually increases with the number of thermal cycling up to 15 cycles, then it takes steady-state up to 30 cycles. It was found that the rate...
Chemical Engineering Transactions, 2017
Prevention of corrosion damage is a key point to assure process safety in the refinery and petrochemical industry. Controlling and stopping corrosion is only possible through the detailed evaluation of all processes related to the corrosion damage. In this work was proposed a methodology to evaluate the corrosion damage during the combustion process in the refinery and petrochemical industry. As a study case, the evaluation of AISI 304 and ASTM A335 P5 steels was realized in an atmosphere generated during the combustion process. The corrosion products formed on each material were simulated at 750 °C in the software HSC Chemistry. As a model mixture for the simulation, it was used the historical chromatographic records from the gas mixture used in a typical furnace from Barrancabermeja (Colombia) refinery. These results were compared with experimental results, in which corrosion coupons of AISI 304 and ASTM A335 P5 steels were installed inside a furnace from Barrancabermeja refinery at 750 °C. The corrosion rate was calculated by gravimetric analysis, and the morphology and composition of the corrosion products were obtained by Scanning Electron Microscopy with X-Ray Microanalysis (SEM-EDS) and X-Ray Diffraction (XRD) analysis respectively; showing similarity between the corrosion products thrown in the simulation. The gravimetric analysis showed that the corrosion rate of ASTM P5 steel was higher than in AISI 304 steel; it was explained because the no formation of an internal protective chromium oxide layer in ASTM P5 steel. On the other hand, the SEM-EDS analysis showed that the corrosion products formed on AISI 304 steel corresponded mainly to iron oxides and spinels. Unlike the corrosion products obtained for ASTM P5 steel, for which only iron-rich layers were formed. Additionally, the EDS analysis revealed carburization and sulfidation in both sheets of steel, although these effects were more representative of AISI 304 steel. Finally, the kinetic study suggested the formation of non-protective oxide layers, which was confirmed through SEM analysis; where were revealed cracks and gaps in the morphology of the oxide layers formed in both sheets of steel. Finally, it is important to mention that the methodology applied in this work is applicable to other steels in typical corrosive environments from the refinery's equipment.