Design and characterization of a cobalt-free stainless maraging steel for laser-based powder bed fusion
Artikel i vetenskaplig tidskrift, 2022

This study presents a new Co-free stainless maraging variant for laser-based powder bed fusion developed using a computational alloy design approach. The goal was to develop an easily printable material with similar performance to 18Ni-300. After screening numerous compositions, Fe-13.2Cr-9.1Ni-1.1Al-0.6Mo-0.5Nb-0.23Ti-0.5Mn-0.5Si (wt.%) was selected. This composition showed excellent printability with low porosity levels. The precipitation strengthening response was evaluated by aging at 500 °C for 15 min, 3 h and 18 h, measuring hardness, tensile strength, and by characterization using atom probe tomography. After 15 min of aging, 90% of the maximum hardness was reached, thanks to formation of (Ni, Al, Nb, Ti, Mn, Si) clusters with a density of 1.5 × 1024 m-3. Between 15 min and 3 h, distinct precipitates formed with a radius of ∼1.4 nm. The precipitates underwent a splitting phenomenon after 18 h, forming several unique Ni-rich precipitates including Ni16Si7(Ti, Nb)6 and Ni3(Al, Ti, Nb, Si). The splitting can be a reason for the slow coarsening rate, as the average precipitate radius after 18 h was only 2 nm. Simulations of the precipitation sequence using PRISMA indicated very rapid and dense precipitation of L12-Ni3X precipitates with a slow coarsening rate, in agreement with experimental observations.

Precipitates

Alloy design

LB-PBF

Maraging

Additive

APT

Författare

Dmitri Riabov

Chalmers, Industri- och materialvetenskap, Material och tillverkning

Karin Frisk

Chalmers, Industri- och materialvetenskap, Material och tillverkning

Mattias Thuvander

Chalmers, Fysik, Mikrostrukturfysik

Eduard Hryha

Chalmers, Industri- och materialvetenskap, Material och tillverkning

S. Bengtsson

Höganäs

Materials and Design

0264-1275 (ISSN) 1873-4197 (eISSN)

Vol. 223 111180

Ämneskategorier

Bearbetnings-, yt- och fogningsteknik

Atom- och molekylfysik och optik

Metallurgi och metalliska material

DOI

10.1016/j.matdes.2022.111180

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Senast uppdaterat

2023-10-27