Publication detail

Residual Stress Distribution in Dievar Tool Steel Bars Produced by Conventional Additive Manufacturing and Rotary Swaging Processes

IZÁK, J. STRUNZ, P. LEVYTSKA, O. NEMÉTH, G. ŠAROUN, J. KOCICH, R. PAGÁČ, M. TUHARIN, K.

Original Title

Residual Stress Distribution in Dievar Tool Steel Bars Produced by Conventional Additive Manufacturing and Rotary Swaging Processes

Type

journal article in Web of Science

Language

English

Original Abstract

The impact of manufacturing strategies on the development of residual stresses in Dievar steel is presented. Two fabrication methods were investigated: conventional ingot casting and selective laser melting as an additive manufacturing process. Subsequently, plastic deformation in the form of hot rotary swaging at 900 degrees C was applied. Residual stresses were measured using neutron diffraction. Microstructural and phase analysis, precipitate characterization, and hardness measurement-carried out to complement the investigation-showed the microstructure improvement by rotary swaging. The study reveals that the manufacturing method has a significant effect on the distribution of residual stresses in the bars. The results showed that conventional ingot casting resulted in low levels of residual stresses (up to +/- 200 MPa), with an increase in hardness after rotary swaging from 172 HV1 to 613 HV1. SLM-manufactured bars developed tensile hoop and axial residual stresses in the vicinity of the surface and large compressive axial stresses (-600 MPa) in the core due to rapid cooling. The subsequent thermomechanical treatment via rotary swaging effectively reduced both the surface tensile (to approximately +200 MPa) and the core compressive residual stresses (to -300 MPa). Moreover, it resulted in a predominantly hydrostatic stress character and a reduction in von Mises stresses, offering relatively favorable residual stress characteristics and, therefore, a reduction in the risk of material failure. In addition to the significantly improved stress profile, rotary swaging contributed to a fine grain (3-5 mu m instead of 10-15 mu m for the conventional sample) and increased the hardness of the SLM samples from 560 HV1 to 606 HV1. These insights confirm the utility of rotary swaging as a post-processing technique that not only reduces residual stresses but also improves the microstructural and mechanical properties of additively manufactured components.

Keywords

neutron diffraction; Dievar; tool steel; hot work tool steel; additive manufacturing; SLM; selective laser melting; rotary swaging; residual stress

Authors

IZÁK, J.; STRUNZ, P.; LEVYTSKA, O.; NEMÉTH, G.; ŠAROUN, J.; KOCICH, R.; PAGÁČ, M.; TUHARIN, K.

Released

22. 11. 2024

Publisher

MDPI

Location

BASEL

ISBN

1996-1944

Periodical

Materials

Year of study

17

Number

23

State

Swiss Confederation

Pages from

1

Pages to

22

Pages count

22

URL

https://www.mdpi.com/1996-1944/17/23/5706

Full text in the Digital Library

http://hdl.handle.net/11012/249982

BibTex

@article{BUT193798,
  author="Josef {Izák} and Pavel {Strunz} and Olena {Levytska} and Gergely {Németh} and Jan {Šaroun} and Radim {Kocich} and Marek {Pagáč} and Kostyantyn {Tuharin}",
  title="Residual Stress Distribution in Dievar Tool Steel Bars Produced by Conventional Additive Manufacturing and Rotary Swaging Processes",
  journal="Materials",
  year="2024",
  volume="17",
  number="23",
  pages="1--22",
  doi="10.3390/ma17235706",
  issn="1996-1944",
  url="https://www.mdpi.com/1996-1944/17/23/5706"
}

Documents

materials-17-05706.pdf