The effect of temperature on fatigue crack growth in liquid metal environments

Abstract

Previous studies of fatigue crack growth in liquid metal environments have shown that at Δ K > Δ K th crack growth rates are approximately one order of magnitude faster than those observed in air. At low Δ K values (low fatigue crack growth rates) and/or where the crack tip is exposed to the liquid metal for long periods of time, crack tip blunting by dissolution occurs. This decreases the rate of crack growth at low Δ K values and results in significantly higher apparent Δ K th values. In this paper the effect of temperature on fatigue crack growth in air and liquid metal environments is investigated using standard LEFM testing procedures. It is found that as the temperature increases the apparent Δ K th value increases significantly. These results are explained in terms of the crack tip blunting hypothesis proposed previously.