Yttrium oxide evaluation as coating to reduce the corrosion velocity in industrial equipment working under combustion environments. Case study: Ferritic 9Cr-1Mo steel

Abstract

The well-known scientific problem about global warming and less cost energy requirement, has been boosting to the petrochemical sector to implement eco-efficiency strategies by promoting the use of critical conditions throughout the traditional chain process of oil refining. In addition, many industrial combustion processes are developed using as energy source a mixture of natural and recovery gases, which added to high temperatures generate potential corrosion atmospheres. Thus, this research aims to try to reduce the pipeline degradation that take place in combustion environments by evaluating an yttrium oxide as coating for the ferritic 9Cr-1Mo steel. This coating was deposited on the substrate by plasma laser deposition, and several growth times were implemented to evaluate its thickness effect. On the other hand, in order to obtain the real combustion atmosphere, a flue gas model composition was selected, which was useful to calculate the theoretical oxidation products by simulation. Finally, those coatings were evaluated at 650 °C and testing times from 1 hour to 100 hours inside the calculated oxidation environment. The main results indicated that even with the tested coatings, the evaluated alloy had a severe corrosion velocity, but lower than without them.