Corrosion Evaluation of a Navy MK50 Weapon Station Friction Brake Assembly
Abstract The presence of corrosion on or within structures is of major concern as corrosion reduces the integrity of the materials which could potentially result in large-scale failures of structures and equipment.1 The United States Navy is an organization that actively works to prevent large equipment failure due to corrosion. One such problem is the corrosion of the friction brake assembly on the MK50 Weapon Station, which has recently been experiencing corrosion between the friction brake and its set screw preventing it from operating correctly. The friction brake was known to be stainless steel; however, the set screw was of unknown composition. Through elemental analysis it was determined that the MK50 Weapons Station friction brake set screw was similar in composition to commonly available black oxide coated steel screws. Electrochemical polarization measurements of the friction brake assembly components revealed that the set screw and the friction brake were electrochemically dissimilar metals which resulted in the galvanic corrosion of the assembly when out at sea. The electrochemical polarization measurements of a stainless steel screw showed a corrosion potential similar to that of the friction brake; therefore, replacing the current set screw with a stainless steel screw would decrease the galvanic potential difference between the set screw and the friction brake. This proposed solution is expected to slow or prevent further corrosion of the MK50 Weapon Station ensuring the combat readiness of the equipment.