Laser beam oscillation welding for fatigue properties enhancement of tailor-welded blanks

•Laser welding without beam oscillation resulted in welds with severe root defects.•Welding with circle and cardioid oscillation mode reduced the root defects, while the lean root was present in the welds made with linear oscillation.•Root defects did not negatively affect the tensile strength of a...

Full description

Saved in:
Bibliographic Details
Published in:Thin-walled structures Vol. 196; p. 111506
Main Authors: Šebestová, Hana, Jambor, Michal, Horník, Petr, Novotný, Jan, Mrňa, Libor
Format: Journal Article
Language:English
Published: Elsevier Ltd 01.03.2024
Subjects:
Beam oscillation
Defect
Fatigue
Laser welding
Tailor welded blanks
Wobbling
Defect
Fatigue
Wobbling
Tailor welded blanks
Laser welding
Beam oscillation
ISSN:0263-8231
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:•Laser welding without beam oscillation resulted in welds with severe root defects.•Welding with circle and cardioid oscillation mode reduced the root defects, while the lean root was present in the welds made with linear oscillation.•Root defects did not negatively affect the tensile strength of a weld joint nor its deep-drawability.•Applying any beam oscillation mode significantly improved the joints' fatigue properties.•The oscillation mode influences the extent of phase transformation and, thereby, the level and distribution of residual stresses. The fatigue properties are influenced both by these factors as well as by the presence and geometry of weld notches. Dissimilar thickness laser welded tailored blanks of two low-alloyed carbon steel grades were fabricated. Laser welds made without beam oscillation exhibited serious root undercuts. Although these notches did not degrade the tensile strength, they were detrimental to the fatigue lifetime of a weld joint. Therefore, laser welds with three different beam oscillation modes to modify the root were examined. Application of beam oscillation improved fatigue properties in all tested cases. The best results were achieved with line oscillation, even though this mode did not suppress weld root notches, suggesting other factors, besides joint geometry, contributing to the resulting fatigue properties.
ISSN:0263-8231
DOI:10.1016/j.tws.2023.111506