Corrosion and Its Inhibition of Mild Steel under Heat Transfer Conditions

Abstract

The corrosion rates of mild steel in a tap water with and without inhibitors were measured under heat transfer and non-heat transfer conditions. Under heat transfer conditions the corrosion rate of mild steel was larger than that measured under non-heat transfer condition. From the results, it was found that the corrosion rate was affected more pronouncedly by the magnitude of heat flux than the temperature at the heat transferring surface. The corrosion rate of mild steel in water containing sufficient concentrations of corrosion inhibitors under heat transfer conditions was almost equal to that under non-heat transfer conditions. The corrosion inhibition occurred at the same concentration of inhibitor for both the heat transfer surface and the non-heat transfer surface. Therefore, it appears that the evaluation of corrosion inhibitors under heat transfer condition will give nearly the same result as that obtained under non-heat transfer conditions. In other words, the effects of inhibitors on the corrosion of heat transfer surfaces can be evaluated by the corrosion measurement of test coupons in laboratory and field without taking heat transfer into account.