AM Science forum Rapid.Tech 3D 2024

Surface treatment of additively manufactured high-alloy austenitic steel parts with the aim to prolong fatigue life

E-PBF process is successfully applied for producing parts out of high-alloy austenitic steel with a moderate nickel content. Pseudo-Jet-PEP process is proved to be more efficient for polishing the E-PBF parts compared to a conventional PEP process.

In this article preliminary results of an interdisciplinary study on high-alloy austenitic steel with medium manganese content are presented, namely the steel X2CrMnNi16-7-4.5. The specimens were manufactured using the powder based electron beam melting technology (EB-PBF). The steel powder for the EB-PBF process was gas-atomised using a vacuum induction-melting gas atomisation (VIGA-1B) unit. For improving the surface integrity of the manufactured specimens they were plasma electrolytic polished (PEP) in a combination with particle blasting. The bath-PEP and pseudo-jet-PEP processes were realised. The EB-PBF process parameters were also optimised in order to reduce the depth of surface notches of the specimens in as-built conditions as well as minimise the building defects, e.g. lack of fusion. The initial results show that while EB-PBF process is well suited for processing X2CrMnNi16-7-4.5 steel, the resulting surface quality requires significant post-treatment efforts for improving its integrity. The efficiency of the used surface enhancement techniques is evaluated in terms of thickness of the removed material, δ, as well as material removal rate MRR and by qualitatively evaluating the resulting surface condition. It is demonstrated that pseudo-jet-PEP holds the promise for being the most effective surface treatment for EB-PBF parts. The optimised parameters for manufacturing and post-treatment processes will be applied for fabricating a bottom bracket of a cargo bike that is topology optimised for prolonged fatigue life.

Presentation language: ENG


Speakers (1)

Kristina Navickaitė

Kristina Navickaitė

Researcher