Tomoya Nagira
;
Houichi Kitano
;
Takashi Kimura
;
Fumiyoshi Yoshinaka
;
Susumu Takamori
;
Takahiro Sawaguchi
;
Takayuki Yamashita
;
Yasuhiro Aoki
;
Hidetoshi Fujii
Description:
(abstract)The dynamics of curved columnar growth and ripple formation in Fe-Mn-Cr-Ni-Si alloys were studied in situ during GTA melt-run welding using synchrotron radiation X-ray imaging with high spatial resolution. In situ observations demonstrated that primary dendrite arm growth ceased when the angle between the growth direction of the primary dendrite arms and the direction of the maximum temperature gradient exceeded 44–49 º at welding speeds of 1–7 mm/s. Consequently, curved columnar grains were formed by changing the growth direction via the development of secondary dendrite arms into primary dendrite arms. Image analysis revealed that a weld ripple, where solutes were highly segregated in the dendrite trunk, was formed by a rapid increase in the interface velocity.
Rights:
© The Author(s) 2025.
Keyword: in situ observation, X-ray imaging, GTA welding
Date published: 2025-08-04
Publisher: SAGE Publications
Journal:
Funding:
Manuscript type: Author's version (Accepted manuscript)
MDR DOI: https://doi.org/10.48505/nims.5774
First published URL: https://doi.org/10.1177/13621718251360932
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Updated at: 2025-09-22 16:30:19 +0900
Published on MDR: 2025-09-22 16:18:41 +0900