The effect of fluid velocity and microstructure on erosion corrosion of two-phase CK45 steel

Abstract

The essential factor to reduce the overall cost in many industries which facing erosion-corrosion phenomenon is the choice of correct design and material selection. The effect of fluid flow on corrosion and erosion–corrosion of materials is a well-recognized phenomenon in chemical and process industries and oil and gas production. The most effective parameter of flow is fluid velocity and best method of determination of the effect of fluid velocity as well as the magnitude of erosion-corrosion synergistic interaction is based on the weight loss measurements. In this study, the effect of fluid velocity on erosive corrosion of two-phase steel CK45 with different microstructures was investigated. These microstructures were formed by austenitizing the samples at 740C° for 2 ​min and then by air cooling and quenching in water or by austempering at 400C° for 2 ​h. Erosion corrosion test was carried out on the water dissolved in 3 ​wt% sodium chloride and 1 ​wt% alumina particles at velocities of 5, 9 and 16 ​m/s. According to the results, the kinetics of erosion-corrosion was linear. Increasing fluid velocity from 5 ​m/s to 16 ​m/s erosion-corrosion rate increased 4 to 6 times depending on the microstructure. SEM examination revealed presence of cavitation phenomenon on the surface of the samples. The results confirm that the bainitic ferrite microstructure exhibited the least damage in the Condition which contain sand particles or cavitation in a corrosive medium.