Galvanic Corrosion of Carbon Steel –Copper in Aerated H2SO4 Under Agitation Conditions

Abstract

Galvanic and free corrosion experiments on carbon steel-copper couple in 3% H2SO4in the presence of NaCl salts were carried out under different operating conditions. The effect of temperature, agitation speed, and air bubbling (O2 concentration) on the free and galvanic corrosion was studied and discussed. The galvanic corrosion was investigated by both weight loss method and by determining the galvanic currents using zero resistance ammeter (ZRA). The results revealed that increasing temperature leads to increase the galvanic corrosion rate and also the free corrosion rate of each metal. Increasing agitation velocity enhanced the galvanic corrosion rate in a manner depending on temperature. The presence of air bubbling increased the corrosion rate and galvanic currents at low air pumping rate, while, at high pumping rate, air bubbling decreased the corrosion rate.

Keywords

• galvanic corrosion
• copper
• carbon steel
• sulfuric acid
• agitation speed