Influence of heat treatment under hot isostatic pressing (HIP) on microstructure of intermetallic-reinforced tool steel manufactured by laser powder bed fusion
Artikel i vetenskaplig tidskrift, 2020

Microstructure and properties of as-built laser powder bed fusion (LPBF) steels differ from the conventional ones, and they may contain some porosity and lack of fusion. Therefore, post-treatments, including hot isostatic pressing (HIP), are used to density the material, and tailor the properties of the final product. Usually, HIP is performed as an operation separate from heat treatment. In the present investigation a new approach was used, in which the whole cycle of the heat treatment was carried out in HIP under pressure, and the influence of HIP on microstructure of an advanced stainless maraging tool steel manufactured by LPBF was investigated. For a comparison, a conventional steel grade of the same chemical composition, after a heat treatment at the same temperature-time conditions, was also characterized. The microstructure of the steel was investigated by means of advanced microscopy and atom probe tomography. The influence of the manufacturing route, heat treatment and HIP on microstructure, austenitic phase fraction and size distribution of precipitates was investigated, and the role of high pressure in stabilization of austenite in the microstructure was discussed. It was concluded that since HIP influences phase transformations, a fundamental understanding of the influence of HIP on microstructure is nececcary, and development of new post processing regimes guaranteeing the best performance of the material is required.

Precipitation hardening

Transmission electron microscopy

Maraging steel

Laser powder bed fusion

Hot isostatic pressing (HIP)

Atom probe tomography

Författare

[Person 4cae391b-c83a-417b-a5c3-46277a7d3969 not found]

Karlstads universitet

[Person 21ba2d5f-712d-4213-bbfe-a1a44d71f93f not found]

Karlstads universitet

[Person bc8b9fc6-05cf-4877-82d8-3d5ba45fab3a not found]

Chalmers, Fysik, Mikrostrukturfysik

[Person 083c5655-7e92-4e97-8901-8e598d7be9cf not found]

Karlstads universitet

[Person 50bced5d-d2f8-4095-98aa-ee3fee59b74c not found]

Karlstads universitet

[Person bcdcf6d7-7982-4c12-a13a-a2cf529aa41b not found]

Uddeholm

[Person b4842456-e376-49e1-acbb-48c5824e962a not found]

Uddeholm

[Person 61cf7600-c96d-4d26-919e-3caa89d938eb not found]

Uddeholm

[Person f423d614-bd00-401a-b727-dde33cbe2d61 not found]

Russian Academy of Sciences

Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing

0921-5093 (ISSN)

Vol. 772 138699

Ämneskategorier

Bearbetnings-, yt- och fogningsteknik

Annan materialteknik

Metallurgi och metalliska material

Infrastruktur

Chalmers materialanalyslaboratorium

Styrkeområden

Materialvetenskap

DOI

10.1016/j.msea.2019.138699

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Senast uppdaterat

2020-11-27