INHIBISI KOROSI BAJA KARBON DI LINGKUNGAN KARBONAT - BIKARBONAT DENGAN INHIBITOR PASIVATOR

• Main Author: Syahri , M.
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/8666
• Institution: Institut Teknologi Bandung

Carbon steel is generally used as the construction material in CO2 absorption systems with 28.9% K2CO3 solution as absorbent. This process can be simulated in a velocity test unit, according to NACE Standard TM 02-70. The electrolyte solution consisted of a mixture of 15.1%(w) K2CO3 + 20%(w) KHCO3. Single faced Carbon steel AISI-C 1010 was used as specimen. The area of specimen is 0.95 Cm2. The experiments were performed at 60, 80, 100 Farenheit C; 0, 400, 800 rpm; without and with 8, 10, 12 and 14 g/l Na-benzoate inhibitor as well as 10, 15, and 20 g/l Vanadate inhibitor. According to anodic polarization curves obtained using CMS 100 Programmable Potentiostat, at a scan rate of 1 mV/s, Carbon steel is passivable in uninhibited carbonate-bicarbonate solution. Carbon steel has shown passive behaviour in mentioned solution treated with > 14 g/l Na-benzoate inhibitor, due to the formation of passive film consist of ri-Fe2O3 and Fe2(OH)2CO3. Meanwhile the presence of >15 g/l Vanadate inhibitor in a similar environments produce a passive film which consist of n-Fe2O3 and FeVO4 on the Carbon steel surface. In uninhibited solution, Carbon steel corrosion rate has increased with increasing temperature, because the temperature rise could disturb the passive film growth. Addition of >14 g/l Na-benzoate inhibitor in Carbonate-bicarbonate solution has increased the corrosion potential of Carbon steel, so a good passivation can be achieved. Whereas with addition of >15 g/l Vanadate inhibitor was not sufficient to maintain decreasing corrosion potential, due to increasing temperature. High stirring rate in uninhibited carbonate-bicarbonate solution could destroy the passive film on Carbon steel surface. With >14 g/l Na-benzoate inhibitor or >15 g/l Vanadate inhibitor in mentioned solution, the corrosion rate of Carbon steel is no longer influenced by the rise in stirring rate. Na-benzoate inhibitor and Vanadate inhibitor have the similar effectivity in the same operation condition.