Mechanical Behaviour of Maraging Steel Processed by Powder Bed Fusion via Laser Beam (PBF-LB) in Different Build Orientations

Abstract

Anisotropy in tensile behaviour, plastic flow behaviour and low cycle fatigue (LCF) behaviour of additively manufactured (AM) maraging steel in different build orientations are presented and compared with conventionally manufactured maraging steel. Also, the effect of heat treatment (namely, solution treatment and ageing) on tensile behaviour and low-cycle fatigue behaviour are discussed. The AM maraging steel showed large anisotropy in mechanical properties in as-built (AB) condition and the anisotropy was reduced after heat-treatment (HT). True stress-true strain data of AM maraging steel in AB and HT conditions have been analysed using Hollomon, Ludwik, Swift, Ludwigson and Voce plastic flow relationships. Ludwigson equation was found to be valid for describing the flow behaviour of the maraging steel. The fatigue life of additive samples was greatly governed by processing defects and their orientation with loading axis and major improvement in fatigue life was obtained after heat treatment. © 2023 Trans Tech Publications Ltd, All Rights Reserved.