Understanding the Differences in Microstructural Evolution between Additively Manufactured and Conventional 18Ni (300) Maraging Steel upon Post-Processing Heat Treatment

Authors:

Shahrzad Sajjadivand (1), Mark Hartnett (2), Mert Celikin (1)

1- School of Mechanical and Materials Engineering, UCD, Belfield, Dublin, Ireland

2- Irish Manufacturing Research, National Science Park, Mullingar, Westmeath, Ireland

Abstract:

This study aims to optimise post-processing heat treatment methodology of 18Ni (300) maraging steel manufactured via Laser-based Powder Bed Fusion (PBF-LB). This is achieved by understanding the effect of post-processing heat treatment on the microstructural evolution and mechanical behaviour of PBF-LB 18Ni (300) maraging steel in comparison to conventionally manufactured 18Ni (300) maraging steel. In-depth materials characterisation was carried out using X-ray diffraction (XRD), scanning electron microscopy (SEM). The analysis reveals microstructural variation in PBF-LB 18Ni (300) maraging steel in as-built condition with noticeable hardness changes. However, solutionising at 850 °C, 950 °C, and 1050 °C lead to a more homogenized microstructure and reduced variation in hardness. A comparison of PBF-LB and conventionally manufactured samples reveals similar hardness levels upon post-processing heat treatment.

DOI:

https://doi.org/10.59499/EP246281376