EPJ Web of Conferences 183, 01058 (2018)
https://doi.org/10.1051/epjconf/201818301058

Tensile Properties of AM Maraging steel

¹ QinetiQ, Fort Halstead, Sevenoaks, Kent, TN14 7BP, UK
² QinetiQ, Bristol Business Park, Coldharbour Lane, Bristol, BS16 1FJ, UK
³ QinetiQ, Cody Technology Park, Ively Road, Farnborough, Hampshire, GU14 0LX, UK
⁴ Surface, Microstructure & Fracture Group Cavendish Laboratory, JJ Thomson Ave, Cambridge, CB3 0HE, UK.

^* Corresponding author : pdchurch@qinetiq.com

Published online: 7 September 2018

Abstract

Additively Manufactured (AM) materials have great potential for producing graded materials, embedded structures and near net complex shapes. AM maraging steel properties have been compared with wrought maraging steel. The comparison featured interrupted tensile tests over a range of temperatures and strain rates. In addition a specially designed Tensile Split Hopkinson Pressure Bar (TSHPB) has been built to test very high strength metals at high strain rates. The results showed that the AM maraging steel was much more ductile than expected and exhibited significant necking under all conditions tested. All the samples exhibited ductile fracture. Although not as ductile as the wrought material, the AM material could be cost effective through economies of scale for complex components. The microstructure contained inclusions which derived from either the powder or the AM process and thus there is significant potential to improve these materials further. A modified Armstrong-Zerilli model was also constructed for these materials and shown to predict the raw experimental data within experimental error using DYNA3D simulations.