Influence of prior fatigue on creep of a ‘non-heat-treated’ alloy steel

Abstract

The effect of prior cyclic deformation on the subsequent creep at 565°C of a 1Cr-Mo-V steel in its ‘non-heat-treated’ condition (i.e. without a final 20 h anneal at 700°C) has been investigated. Fatigue damage in the ralige 5–36% of life produces a reduction in creep rupture time of between 30 and 38%. A very slight fall in ductility is observed, in contrast to the previously reported behaviour of the ‘heat-treated’ alloy in which the fracture strain doubles following prior fatigue. The minimum creep rate is enhanced by up to 40%, while the extent of ‘steadystate’ creep is correspondingly reduced.