Abstract
A development program to further increase the competitiveness of the direct electrical heating technology has been initiated. By increasing the power frequency from 50/60 to 100-200 Hz, less current is needed to develop the same heat generation in the pipe. A test program is running with the purpose of studying AC corrosion on the cathodically protected steel pipelines at higher frequencies. This article presents results from initial tests, showing that corrosion on steel specimens are present at 60 Hz, but that zero or very little corrosion is present at 100 and 200 Hz. On the aluminum specimens, corrosion rate is reduced by 55 % from 60 to 100 Hz. and is somewhat further reduced at 200 Hz. Copyright © 2017 by the International Society of Offshore and Polar Engineers (ISOPE).