Influence of Reversion Austenite on Fatigue Strength of Shot-Peened Maraging Steel

Abstract

A maraging steel has low fatigue strength for its high static strength. In the present study, the influences of shot peening and reversion austenite on fatigue strength of a maraging steel were investigated to achieve the improvement of fatigue strength of the steel. By shot peening, fatigue strength was markedly increased and fracture mode changed in order of surface, combined type of surface and interior and interior fractures with decrease of the stress level. Fatigue strength in the surface fracture region was still increased by double shot peening which improved the surface integrity i.e. surface roughness, hardness and compressive residual stress. On the other hand, fatigue strength in the interior fracture region was increased by the formation of reversion austenite where as it was not affected by the shot peening condition.