The Influence of Flow Rate, Sand and Inhibitor on Iron Carbonate Scales under Erosion-Corrosion Conditions using A Submerged Impingement Jet

摘要

This study focuses on the effects of flow rate, sand and corrosion inhibitor on the performance of FeCO_3 scale formed on the X65 carbon steel in a submerged impinging jet (SIJ) system in CO_2 saturated environments. The experiments were conducted at a temperature of 70 °C, pH of 5.32 and 26.4 N/m2 wall shear stress (t_w). Weight gain/loss was measured for as-received X65 specimens and specimens before and after removing corrosion scales in both uninhibited and inhibited systems. In addition, the hardness of the surface specimens and layers was measured using a nano-indenter. This was supported by post-test analysis of samples using scanning electron microscopy (SEM) to assess both the nature and the thickness of the scales and energy dispersive X-ray spectroscopy (EDX) to reveal the elemental composition and the possible salts forming these protective films. It was found that introducing 25 ppm of inhibitor was sufficient to reduce the total weight loss of both the as-received surfaces and the scaled surfaces by 89% and 87% respectively.