Cumulative fatigue damage assessment and life predictions of as-forged vs QT V-based MA steels using two-step loading experiments


This study examines the fatigue damage accumulation process associated with a commonly produced forged vanadium-based microalloyed (MA) steel and its comparison with its quenched and tempered (Q&T) counterpart at the same hardness level. The advantage of MA steels compared to the traditional Q&T steels is the elimination of the costly quenching and tempering processes. Completely reversed strain-controlled two-level block loading tests were conducted on smooth axial specimens at room temperature. Under multi-level block cycling, the two steels displayed different characteristics, though they showed similar behaviour in constant amplitude fatigue. Therefore, a key to successful, assessment of fatigue damage accumulation under variable amplitude service loading is selection of an appropriate cumulative fatigue life prediction model which reflects the material's damage characteristics. The effectiveness of several cumulative fatigue damage models and their life prediction capabilities are evaluated using the experimental data.

Publication Title

Proceedings of the Institution of Mechanical Engineers Part L: Journal of Materials: Design and Applications