Papers by Keyword: Atmospheric Corrosion

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 present study deals with the investigation of the long term atmospheric corrosion phenomena for galvanized steel sheet in the region of Addis Ababa in Ethiopia using various atmospheric corrosion models. Addis Ababa have transforming atmosphere type of urban/industrial atmosphere, and these changes are going to affect the atmospheric corrosion phenomena for galvanized steel sheet used in this region, which is investigated through atmospheric corrosion models using atmospheric data collected from National Meteorology Agency, Ethiopia for 21 years from 2000 to 2020. Atmospheric corrosivity category for Addis Ababa is determined, and it is found that with little deviation in atmospheric pollutant these categories can shift between C2 and C3 corrosivity category for galvanized steel sheet atmospheric corrosion. Further to study the atmospheric corrosion of galvanized steel sheet, standard atmospheric corrosion models were employed namely Feliu et al. model and Kucera et al. model. These studies corroborate the findings of atmospheric corrosion of galvanized steel sheet and cross verified with the similar region atmospheric corrosion experimental studies performed earlier on the same material. All the atmospheric corrosion models confirmed the trend of the atmospheric corrosion of galvanized steel sheet in the region of urban/industrial atmosphere type. And based on the comparative analysis of all models predictions with experimental results in literature, it is confirmed that the atmospheric corrosion model results are reliable for the study of short and long period of atmospheric corrosion of galvanized steel sheet in Addis Ababa region.

Abstract: Stainless steel may be susceptible to localized corrosion. Despite this fact, still too many infrastructures are planned with an inadeguate metal chemical composition or placed in wrong environments. In most cases, a clear underestimation of these factors affects the stainless steel durability. These unexpected issues cause a significant technical and economical impact. In this work, several case studies of Inox exposed to unfavorable environmental conditions are presented. A wide range of structures, such as house handles, a swimming pool, a parapet, an industry plant and a waste water collection tank are investigated with respect to the corrosion behavior. Temperature and humidity cyclic variation, promote the enrichments of aggressive agents and lead to degradation. A too low Molybdenum content of the steels is inadequate for some type of structures and service conditions. The weldability changes depending on the steel type and along the thermally affected zones, intergranular corrosion may appear. In addition, a galvanic contact of the stainless steel with existing low alloyed steels components promotes the deterioration of the latter.

Abstract: The paper presents approaches to solving the problem of protecting equipment against corrosion, aging and damage due to biological reasons, which is one of the most urgent practical problems. The practical significance of this problem is relevant when using machinery both for its intended purpose and during storage. As one of the research areas, the urgency of the problem determines the testing of new technologies and conservation materials developed on a fluorine-containing surfactant. Due to the fact that the preservation of equipment during long-term storage implies its being in a mothballed state for long periods of time - up to 12-15 years, it is rather inefficient to carry out full field tests due to a significant amount of time spent on the introduction of new technologies and their significant obsolescence during tests. Therefore, accelerated laboratory and climatic tests in accordance with standards and GOSTs were selected as the main test methods.

Abstract: The objective of this study is to carry out an atmospheric corrosion analysis on low carbon steel in the form of plates and elbows in the port area of Belawan. The exposure of the test specimen was carried out at five locations for 12 months. The location points are notated as A, B, C, D, and E. The process of specimen exposure and data collection followed the ASTM G-1 and ASTM G-50 standards. The measurement results indicated a slight difference in the corrosion rate at each location. Location C and D have the highest corrosion rate and location A has the lowest corrosion rate. Meanwhile, for locations B and E have a corrosion rate value that is not much different from location A. This difference in value is probably a consequence of the distance from the exposure location to the seaside. Locations C and D are adjacent to the seaside while the other locations are not. The steel plate has an average value of corrosion rate 0.2214 mpy and steel elbow has a rate of 0.2412 mpy. From the measurement results obtained, the two specimens exposed at each location are still in the "outstanding" category.

Abstract: Corrosion is one of the main causes of early failure of infrastructure both for public housing facilities and public facilities in downtown Langsa. This corrosion is caused by air pollution generated from motor vehicle and household industry exhaust fumes and exhaust smoke from the nearest palm oil mill industry from the city of Langsa. Related to air pollution, its sustainability should be a concern regarding environmental impacts that occur, one of which is atmospheric corrosion. This study aims to analyze the impact of the effects of pollution on infrastructure corrosion on construction steel which is often used on infrastructure in the city of Langsa and the palm oil mill industry. There are five types of steel model infrastructure consisting of strips of plate steel, elbow steel, cylinder steel, plate steel, and low carbon steel market have become specimens. Calculation of corrosion rate using the method of mass loss by reference to ASTM standard G50, the location selected above buildings in downtown Langsa and palm oil mill industry. The results of the study for one year showed the level of corrosion rate that occurred in 5 types of steel construction is still relatively safe or its relative corrosion resistance can be classified in the outstanding category (<1 mil per year). The conclusion is that 5 types of construction steel that have been tested, are resistant to corrosion, and are suitable for use as the main construction material in Langsa City and the palm oil mill industrial environment.

Abstract: Due to the large number of stainless steels with different chemical composition and different microstructure the selection of the suitable material represents a huge challenge. In order to facilitate the appropriate grade selection, in the current European standard EN 1993-1-4 a procedure is defined based on the use of a look-up table considering the key variables that influence the selection of stainless steels. The table uses descriptions that competent designers should be able to readily understand or define without prior knowledge. The output from the look-up table is used to select alloys based on a Corrosion Resistance Class (CRC) from I to V. The advantage of this approach is that the designer simply specifies the relevant CRC and does not need to consider in detail which of the many (very similar) alloys to specify.

Abstract: This work deals with the design of fringe capacitance based non-contact type liquid level sensor employing self-compensation feature. The existing capacitive type sensors require additional compensation to overcome the problem of various stray capacitances, specifically due to atmospheric corrosion. This paper emphasizes on the selection of suitable material to accomplish the self-compensation feature in corrosive environment. Rate of attack of corrosion is studied on Copper (Cu) and Aluminium (Al) samples under drizzling environment. Visual Analysis of SEM images of samples exposed for different durations reveal that Al protects itself from the corrosion. Further, performance evaluation of two sensor units with Cu and Al electrodes under the same drizzling environment beside the respective samples indicate that sensor with Al electrodes facilitates the feature of self-compensation in corrosive environment. Further, the sensor is interfaced with Siemens PLC-S200 for liquid threshold level monitoring.

Abstract: This paper studies the atmospheric corrosion characteristics of grid metal frame equipment in Chongqing. Through the standard field test method of atmospheric corrosion -"exposure" method, this study carried out the substation site hanging test of the Q₂₃₅ steel of the power transmission and transformation engineering structural material in the atmospheric environment, and mastered the corrosion data of Q₂₃₅ steel in different corrosion stages. It was found that the morphology, quantity and characteristics of corrosion products on the metal surface varied greatly with the progress of corrosion. According to the metal corrosion morphology of different corrosion time, combined with image processing technology and wavelet transform algorithm, the parameters such as gray mean M, corrosion standard deviation σ_m, corrosion energy E, and energy percentage of wavelet image coefficient were selected as corrosion characteristic variable. At the same time, the BP neural network algorithm was used to qualitatively evaluate the corrosion state of the electrical equipment metal. By testing the on-site samples of the two substations, the corrosion state values of the samples were 0.946 and 0.8071, respectively, which is consistent with the actual corrosion degree, and the system had a good evaluation result.

Abstract: Damage due to atmospheric corrosion on metal structures is a significant aspect for both the design of new constructions and the maintenance of existing buildings. The paper discusses the corrosion depth trends for steel structures comparing an experimental campaign of measurements, given by Fratesi in 2002, with literature 2^nd level models calibrated from experiments on immersed elements, literature models based on testing in atmosphere and standard codes (i.e. EN ISO 9224 and EN 12500). Results show a significant variability of values using different models and codes. In addition, the paper underlines that literature studies and codes neglect specific models for nineteenth-century “wrought iron” constructions, that are very sensitive to corrosion phenomena. Based on this, the paper discusses results obtained by a new interpretative model developed by authors for the prediction of corrosion depth on wrought iron structures.