Multiaxial fatigue behaviour of maraging steel produced by selective laser melting

Abstract

This paper studies the multiaxial fatigue behaviour of maraging steel samples produced by selective laser melting. Hollow cylindrical specimens with transverse circular holes are subjected to different in-phase bending-torsion loading scenarios. Fatigue crack initiation sites and fatigue crack angles are predicted from the first principal stress field. Fatigue lifetime is computed using a straightforward approach, based on a one-parameter damage law, developed via uniaxial low-cycle fatigue tests. The cyclic plasticity at the notch-controlled process zone is accounted for by combining the equivalent strain energy density concept and the theory of critical distances within a linear-elastic framework. Regardless of the multiaxial loading scenario, experimental observations and predicted lives are very well correlated.

Keywords

• Multiaxial fatigue
• Bending-torsion
• Maraging steel
• 18Ni300 steel
• Selective laser melting
• Strain energy density