This study examines very low current iron electroplating as a treatment method for mitigating the growth of corrosion fatigue cracks in mild steel tube. The goal is to improve corrosion resistance and slow fatigue crack growth in 2-inch (10-cm) diameter steel tubes. A novel treatment delivery method developed in this work uses a traveling electrode that applies the treatment during transit along a tube interior over a length of 200 ft in length. The traveling electrode enabled the delivery of high current densities along the tube without drawing large currents from the power source. A key difficulty is getting the plating current to be applied evenly while the electrode is traversing a sharp bend in the tubing which can turn 180⁰ over a distance of 70 cm (~2 ft). In scaled lab testing, iron was plated onto the steel substrate using a 0.02 mA/cm2 current density wherein the drive electrode was located at eccentric positions that were well away from the center of the tube. This study examined the treatment time increase needed to treat tube bends when the drive electrode was located eccentrically away from the tube center. These findings were used to anticipate electrode travel velocity, overall treatment time, as well as the current density requirements for a given treatment.
