The Effect of Product Form Upon Fatigue-Crack Growth Behavior in Alloy 718

Abstract

Five different product forms (sheet, plate, bar, forging, and weldments) all taken from the same heat of Alloy 718 were tested at five different temperatures in each of two different heat-treated conditions. In general, no consistent effect of product form was noted for any of the wrought forms (sheet, plate, bar, or forgings). However, the crack growth rates were higher in weldment specimens than in wrought specimens for some test temperature/heat-treatment combinations. The present results suggest that product form did not influence the heat-to-heat variations noted previously in crack growth studies on wrought Alloy 718.