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Differences in phase transformation in laser peened and shot peened 304 austenitic steel

Starman, Bojan ; Hallberg, Håkan LU orcid ; Wallin, Mathias LU ; Ristinmaa, Matti LU orcid and Halilovic, Miroslav (2020) In International Journal of Mechanical Sciences 176.
Abstract
Laser Shock Peening (LSP) and Shot Peening (SP) are processes used to mechanically alter the surface properties of metals by inducing a transient high-pressure wave by a laser pulse or by a high-velocity impact of a peening particle. Both processes aim to induce compressive residual stresses near the surface and the level of residual stresses obtained from SP or LSP is similar. When austenitic steel is peened, martensitic phase transformation takes place. It has been observed in experiments that the amount of martensite in shot-peened surfaces is significantly higher than in laser peened surfaces. The cause of these differences is, however, not yet fully explained and the available explanations are often conflicting. In this study, both SP... (More)
Laser Shock Peening (LSP) and Shot Peening (SP) are processes used to mechanically alter the surface properties of metals by inducing a transient high-pressure wave by a laser pulse or by a high-velocity impact of a peening particle. Both processes aim to induce compressive residual stresses near the surface and the level of residual stresses obtained from SP or LSP is similar. When austenitic steel is peened, martensitic phase transformation takes place. It has been observed in experiments that the amount of martensite in shot-peened surfaces is significantly higher than in laser peened surfaces. The cause of these differences is, however, not yet fully explained and the available explanations are often conflicting. In this study, both SP and LSP are modelled using an elasto-viscoplastic model that also account for martensitic phase transformation. The analyses show that LSP and SP are fundamentally different from a mechanical point of view. By tracing the stress trajectories in the principal stress space, it is shown that martensite formation and plastic straining are highly dependent on the intensity of the individual components of hydrostatic and deviatoric stress, which evolve differently in the two processes. (Less)
Abstract (Swedish)
Laser Shock Peening (LSP) and Shot Peening (SP) are processes used to mechanically alter the surface properties of metals by inducing a transient high-pressure wave by a laser pulse or by a high-velocity impact of a peening particle. Both processes aim to induce compressive residual stresses near the surface and the level of residual stresses obtained from SP or LSP is similar. When austenitic steel is peened, martensitic phase transformation takes place. It has been observed in experiments that the amount of martensite in shot-peened surfaces is significantly higher than in laser peened surfaces. The cause of these differences is, however, not yet fully explained and the available explanations are often conflicting. In this study, both SP... (More)
Laser Shock Peening (LSP) and Shot Peening (SP) are processes used to mechanically alter the surface properties of metals by inducing a transient high-pressure wave by a laser pulse or by a high-velocity impact of a peening particle. Both processes aim to induce compressive residual stresses near the surface and the level of residual stresses obtained from SP or LSP is similar. When austenitic steel is peened, martensitic phase transformation takes place. It has been observed in experiments that the amount of martensite in shot-peened surfaces is significantly higher than in laser peened surfaces. The cause of these differences is, however, not yet fully explained and the available explanations are often conflicting. In this study, both SP and LSP are modelled using an elasto-viscoplastic model that also account for martensitic phase transformation. The analyses show that LSP and SP are fundamentally different from a mechanical point of view. By tracing the stress trajectories in the principal stress space, it is shown that martensite formation and plastic straining are highly dependent on the intensity of the individual components of hydrostatic and deviatoric stress, which evolve differently in the two processes. (Less)
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; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
International Journal of Mechanical Sciences
volume
176
article number
105535
pages
18 pages
publisher
Elsevier
external identifiers
  • scopus:85079635579
ISSN
1879-2162
DOI
10.1016/j.ijmecsci.2020.105535
language
English
LU publication?
yes
id
2d47f95c-1d4e-4213-970d-09071dbf1424
date added to LUP
2020-02-21 08:24:26
date last changed
2022-04-18 20:42:07
@article{2d47f95c-1d4e-4213-970d-09071dbf1424,
  abstract     = {{Laser Shock Peening (LSP) and Shot Peening (SP) are processes used to mechanically alter the surface properties of metals by inducing a transient high-pressure wave by a laser pulse or by a high-velocity impact of a peening particle. Both processes aim to induce compressive residual stresses near the surface and the level of residual stresses obtained from SP or LSP is similar. When austenitic steel is peened, martensitic phase transformation takes place. It has been observed in experiments that the amount of martensite in shot-peened surfaces is significantly higher than in laser peened surfaces. The cause of these differences is, however, not yet fully explained and the available explanations are often conflicting. In this study, both SP and LSP are modelled using an elasto-viscoplastic model that also account for martensitic phase transformation. The analyses show that LSP and SP are fundamentally different from a mechanical point of view. By tracing the stress trajectories in the principal stress space, it is shown that martensite formation and plastic straining are highly dependent on the intensity of the individual components of hydrostatic and deviatoric stress, which evolve differently in the two processes.}},
  author       = {{Starman, Bojan and Hallberg, Håkan and Wallin, Mathias and Ristinmaa, Matti and Halilovic, Miroslav}},
  issn         = {{1879-2162}},
  language     = {{eng}},
  publisher    = {{Elsevier}},
  series       = {{International Journal of Mechanical Sciences}},
  title        = {{Differences in phase transformation in laser peened and shot peened 304 austenitic steel}},
  url          = {{http://dx.doi.org/10.1016/j.ijmecsci.2020.105535}},
  doi          = {{10.1016/j.ijmecsci.2020.105535}},
  volume       = {{176}},
  year         = {{2020}},
}