Influence of High Pulsed and Continuous Magnetic Fields on the Corrosion and Microstructure of Metallic Conductors.

摘要

Corrosion is among the most costly and severe maintenance problems the US Navy faces on a daily basis. As the US Navy works towards fielding an all-electric ship, it is unclear how the corrosion rate of its structural and current conducting alloys will be impacted when they are repeatedly exposed to the high continuous magnetic fields from external and self-induced sources. The high currents that propel the ship and other complex electrical loads induce these magnetic fields. Experimental results collected from exposure of four engineering alloys to continuous magnetic fields and high-pulsed currents will be presented. The materials tested include 304 stainless steel, 416 stainless steel, 1018 steel, and 8620 steel as these offer structural integrity as well as both magnetic and nonmagnetic properties. A 3.5% NaCl aqueous solution is employed as the electrolyte for all experiments. Samples have been exposed to a continuous 0.45 T magnetic field generated by a DC electromagnet, and by a high-pulsed current from a capacitive pulsed power supply sinking up to 9000 A, respectively. Potential vs. time, anodic polarization, and linear polarization experiments have been conducted to measure and understand the kinetics behind the corrosion process along with the possible impact of the magnetic fields. After the Potential vs. Time experiments, SEM examinations have been conducted to compare baseline samples not exposed to magnetic fields to those, which have been exposed to magnetic fields and to those exposed to high-pulsed currents. The experimental setups and the results of the experiments performed thus far will be discussed.