Cathodic Protection of Highly Complex and Shielded Components

Abstract With the advent and application of Impressed Current Cathodic Protection (ICCP) systems to confined spaces, the ability of an externally controlled ICCP system to effect sufficient cathodic protection to internal components is questionable. This paper seeks to evaluate the ability of ICCP systems to provide adequate corrosion control for confined and sensitive surfaces. Both a boundary element and a physical model were utilized to understand the effects of current distribution within a confined space, through a 1.27 mm gap. Initially, tests were performed to quantify polarization levels in a simplified parallel plate configuration. Then more complicated geometries and materials were modeled to effectively evaluate real world scenarios. Previous tests have determined that adequate cathodic polarization is achieved for simple and complex geometries at the increased driving voltages experienced with sacrificial anode systems. The results of this work provide evidence that adequate cathodic protection may be provided at controlling potentials more electropositive to conventional galvanic cathodic protection system.