Volume 13, Issue 4 (July 1985)
Effect of Misalignment on the Time to Rupture
The materials tested were a low-alloy steel in three conditions of heat treatment and a high-alloy steel in two conditions of heat treatment. The heat treatments were chosen to provide specimens with various notch strength ratios. Notch rupture tests of these five materials were made with various degrees of misalignment. When heat treated to attain the highest notch strength ratio, the low-alloy steel showed no significant change in time to rupture for the range of misalignment tested. The corresponding high-alloy steel specimens showed approximately 3% reduction in time to rupture for each 1% increase in bending strain. For the high-alloy steel, the amount of reduction in time to rupture appears to be almost independent of the notch strength ratio. In contrast, the low-alloy steel showed a reduction in time to rupture of approximately one half that of the high-alloy steel at a notch strength value near unity and almost twice that of the high-alloy steel at the lowest notch strength ratio tested.