Browsing by Author "Munasinghe, RGN De S"

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item: Conference-Full-text
Corrosion behavior of steel in different atmospheric conditions
(The Engineering Research Unit, University of Moratuwa, 2013-02) Adikari, AAMT; Munasinghe, RGN De S; Jayatiieke, S; Rodrigo, R
Corrosion of metals makes a large impact on the remedial actions to prevent structures, corrosion the corrosion that economy of a country. Therefore, it is important machinery and vehicles from corrosion. Among the various types of occurs in the atmosphere is known as atmospheric corrosion and it accounts for more failures than other types oj corrosion. To take preventive actions against atmospheric corrosion of metals, it is essential to study the corrosivity of the atmosphere by analyzing factors that influence it. The corrosivity of the atmosphere mostly depends on several atmospheric variables, such as relative humidity, temperature, rainfall, chloride deposition rate, pollutant gases like nitrogen and sulfur oxides. In order to study the severity of the atmosphere which promotes the used structural materials mild steel, stainless steel 304 and 316 conditions. Two corrosion test panels to take metal corrosion three types of commonly were exposed in two different atmospheric placed in two geographical locations and loss of weight due to corrosion was continuously measured in all three types of metals. The atmospheric variables in the two locations were also continuously recorded. Finally, these data were fitted with the power model in order to predict the rate of corrosion under particular atmospheric conditions. With the predicted corrosion rate under a particular atmospheric condition it is possible to take necessary> preventive measures during the design or in the service of metallic structures, machinery and vehicles etc. The broad aim of this research work is to collect adequate data to develop a corrosion model to predict the corrosion rate in any atmospheric environment in Sri Lanka using measured atmospheric variables and thereby establish a 'corrosion map'for Sri Lanka.
item: Conference-Full-text
Effect of penetration of corrosion on the load- bearing capacity of mild steel
(IEEE, 2018-05) Jayasooriya, ED; Piyathilake, SAKVM; Sivahar, V; Munasinghe, RGN De S; Chathuranga, D
The field of Metallurgical Engineering associated with the service life of corroded metallic structures has been studied in extensive detail, the world over. Most of the theses in this area have focused only on the general attack (uniform corrosion) on steel structures in a range of atmospheres. This study sought to examine whether the penetration of corrosion beyond the general attack into the bulk material, has a significant effect on the load-bearing capacity of mild steel structures. Mild steel samples were corroded in an aggressive atmosphere over a 5-month period, subjected to periodic tensile testing and corrosion mass-loss analyses, and examined under optical and electron microscopy. Through the identification and measurement of the penetration of corrosion using scanning electron microscopy, this research managed to correlate corrosion mass-loss and tensile load-loss data with said microscopic measurements. The results showed that the actual breaking loads deviated negatively from the expected loadbearing capacity, which was determined through conventional methods. This deviation showed a close correlation to the increase of penetration of corrosion with time.
item: Conference-Extended-Abstract
Magnetic induction assisted levitation of metallized particles in sintered dela Iron ore pellets
(2010) Gobikrishna, S; Raguratnam, E; Guluwita, SP; Munasinghe, RGN De S; Fernando, WLW
Degree of metallization is on important characteristic of reduced iron ore pellets when determining its applicability in the iron and steel making industry. If the degree of metallization is about 95 -97% induction furnace could be used in making alloy steels. If the degree of metallization is less, it may be employed in an arc furnace. In the present research a simple and economical method has been suggested to examine the degree of metallization of reduced iron ore pellets by magnetic induction assisted levitation. This may be adopted to quantify the degree of metallization of reduced pellets after a suitable calibration. Further research is in progress
item: Thesis-Full-text
Prediction of corrosion behavior of mild steel in different Sri Lankan atmospheric conditions
Adikari, AAMT; Munasinghe, RGN De S
Corrosion is defined as the deterioration of materials due to the reaction with its environment. According to the physical nature of environment, corrosion can be categorized as 'corrosion in atmosphere', 'corrosion in water', 'corrosion in sea', 'corrosion in soil' etc. Among them, corrosion of steel in atmosphere is identified as one of most important type of corrosion. Because studies show that corrosion cost of a country may vary between 1 to5% of their GDP and about one half of that cost is due to atmospheric corrosion. Corrosion problem cannot be completely eliminated but it is possible to control by methods known as 'corrosion management systems'. Corrosion model is a one of the best tool that can be used for atmospheric corrosion management. Use of a corrosion model as a tool for corrosion prevention is the common practice in many other countries, but using this method is not a popular practice in Sri Lanka due to non availability of such model. Therefore, this project was carried out for the formulation of an atmospheric corrosion model that can be applicable in Sri Lankan atmosphere. For this purpose, by reviewing internationally published literature a model structure was proposed. Then field exposure programs were conducted to obtain data required for model calibration. The model was calibrated with the obtained data and test has been done for goodness of fit and the model shows considerably acceptable goodness of fit with more than 80% of data are within the ±10% deviation from actual value. Finally, a completely different set of samples were placed in different locations and data gathered were used to find out the validity and forecasting capability of the model,. The model shows a good performance in forecasting capability with acceptable deviations.