الفهرس | Only 14 pages are availabe for public view |
Abstract Acid pickling is one of the most applications of using acid solutions in the oil and gas industry. Carbon steel is one of the most popular alloys in the oil and gas industry. After removing the oxide scales during acid pickling, the interaction of acid solutions with the steel surface can cause corrosion in the base metal. The problem will lead to economic losses and environmental problems due to steel corrosion, which can contribute to some leakage. To solve this problem, many carbon steel corrosion protection strategies are used in acid media such as corrosion inhibitors. The inhibitor’s mechanism to reduce steel’s corrosion rate is the creation of a protective film from the corrosion solution on the steel surface. Nowadays, several studies have focused on natural products that can be used as green corrosion inhibitors, such as extracts from various plants. Sodium Alginate Grafted Poly (Acrylamide) (SG-g-PAM) as a green eco-friendly environment corrosion inhibitor was studied in our thesis to replace the commercial corrosion inhibitor that used during acid pickling with 0.2 M citric acid solution in carbon steel. Chapter One: Introduction The introduction contains a background as follows: • Theoretical background. • What are the chemical cleaning and its stages and applications and its problems. • Chemical cleaning working conditions and the chemicals used. • The mechanism of acid pickling and passivation on the carbon steel surface. • Corrosion inhibitors: how they work, types, advantages, and disadvantages. Chapter Two: Literature Review The second chapter contains a survey of previous studies for several points in the subject of the study, such as the application of various natural environment-friendly corrosion inhibitors in acid pickling and the different types of acids used in acid pickling. Chapter Three: Materials and Methods This chapter contains the practical methods used in this study as follows: • Preparing sodium alginate polyacrylamide as an environmentally friendly corrosion inhibitor., Studying the inhibitor efficiency in 0.2 M citric acid solution that used in the acid pickling on the carbon steel of ’grade A672’ by using weight loss test and electrochemical tests (Electrochemical impedance spectroscopy & Potentiodynamic polarization) at the following temperatures: 30, 45, 65 and 75 ° C., A scanning electron microscope (SEM) was used to study the effect of chemical cleaning stages on the surface of carbon steel and also study the surface morphologies in the absence and presence of an inhibitor in a 0.2 M citric acid solution at the temperature of 30 and 65 °C., XRD was applied to study surface before and after pickling and passivation., FTIR spectrophotometer used to determine the function groups of SG-g-PAM. |