Influence of annealing temperature on low cycle fatigue and cyclic creep of ultra high strength low alloy steel

Low cycle fatigue and cyclic creep at ambient temperature of UHSLA, the Czech equivalent of the American 300M steel, were studied for different heat treatment (HT). Optimal properties correspond to the annealing temperature of 300 degrees C that also provides the most favourable complex of other mechanical properties. Cyclic creep threshold curves were proved to exist for this steel, as well. Nevertheless, their relation to the fatigue life drop is significant only for high annealing temperatures. Results show that steel investigated exhibits better mechanical properties than the ROL N steel currently used in the Czech military aircraft and motor-car industry.