Thermal-chemical-mechanical gun bore erosion of an advanced artillery system part two: modeling and predictions

Thermal-chemical-mechanical gun bore erosion models and predictions are described for an advanced artillery system and its associated laboratory-firing simulator system. Both high and low contractile chromium electroplated coating types are evaluated. These models and predictions are based on bore erosion theories and mechanisms developed previously by these authors for each of the coating types used in this live fired system and its simulator. These theories and mechanisms are in turn based on associated bore erosion measurements and characterizations acquired previously for this system and it simulator. This artillery system consists of a cannon, charge, projectile, and additives. Its simulator consists of a vented combustor, charge, and additives. Gun bores typically have an erosion barrier of 0.05-0.50 mm high or low contractile chromium electroplated coating on a nickel-chromium-molybdenum-vanadium high strength gun steel substrate. Gun system firing rates, zones, coating types, and coating thickness vary. Our coating-substrate gun system erosion models were developed from rocket nose-tip and nozzle erosion models. The key calculations of the model are gas and gas-wall thermochemistry, interior ballistics, boundary layer with mass addition, wall temperatures (surfaces, interfaces, micro-pits, pits), and coating-substrate wear and erosion. These erosion models and predictions are used to provide a comprehensive estimate of erosion life and to enable erosion mitigation efforts for each of the coating types used in this advanced artillery system and its simulator.