Evaluation of corrosion resistance of coatings applied to Process equipment used in yellowcake production plant

Abstract

Austenitic stainless steels can withstand acidic environments relatively well. The sulfuric acid used in the process lines and the relatively high temperatures of the liquid (60oC) can cause general corrosion and pitting of the tank, which may eventually cause sudden failure. In order to reduce corrosion rates and prevent tank thickness from decreasing, it is imperative that appropriate coating systems be employed, since materials and the construction of new tanks are extremely expensive. In this study, stainless steel samples were coated with ceramic polymer-reinforced polymer coatings, graphite primers, glass liners, fluoroethylene chlorinated ethylene chloride, and fiber-reinforced vinyl esters. In order to evaluate and analyze the applied coatings, test methods such as holiday detection, hardness, adhesion strength, salt spraying, and electrochemical impedance spectroscopy were used. As a result of excellent adhesion to substrates regardless of sulfuric acid or chlorine exposure, glass linings are not just anticorrosive but also highly durable.

Keywords

• stainless steel
• sulfuric acid
• coating
• corrosion
• electrochemical impedance spectroscopy