Casting Solutions for Readiness Modeling of Steel Casting Performance: Dimensions and Distortion

Casting distortions are unacceptable dimensional changes resulting from stresses during solidification and cooling which can result in repair work or scrapped castings. Both the mechanical behaviors and properties of the steel and the sand mold affect the final casting dimensions through mold expansion, and by constraining the casting from free contraction, which introduces stresses and additional distortions. Distortions can lead to a lengthy trial-and-error process of modifying pattern allowances to meet dimensional requirements. In the past, foundries relied on rules-of-thumb, lengthy trial-and-error processes, and excessive machining allowances to meet dimensional tolerances. New dimensional predictive capabilities are especially needed for optimizing the dimensional performance of the thin-walled and light-weight steel castings needed in advanced weapon systems. The research and developments described here were undertaken to address deficiencies of computer models to predict final dimensions and distortions of steel castings.