Zhang, Y.; Qin, Y.; Zhao, F.; Liang, M. Improving the Microstructure and Mechanical Properties of Laser Welded Al-Si Coated 22MnB5/ Galvanized Steel Joint Added by Nickel. Preprints2023, 2023071453. https://doi.org/10.20944/preprints202307.1453.v1
APA Style
Zhang, Y., Qin, Y., Zhao, F., & Liang, M. (2023). Improving the Microstructure and Mechanical Properties of Laser Welded Al-Si Coated 22MnB5/ Galvanized Steel Joint Added by Nickel. Preprints. https://doi.org/10.20944/preprints202307.1453.v1
Chicago/Turabian Style
Zhang, Y., Feng Zhao and Min Liang. 2023 "Improving the Microstructure and Mechanical Properties of Laser Welded Al-Si Coated 22MnB5/ Galvanized Steel Joint Added by Nickel" Preprints. https://doi.org/10.20944/preprints202307.1453.v1
Abstract
To weaken the harm of Al-Si coating and increase the strength of welded joint, variable thickness of Ni foil (Ni, an austenitic formation element) was added into the lap laser welding Al-Si coated 22MnB5 hot stamping steel/galvanized steel joints. The joints' weld appearance, microstructure, and mechanical properties were explored. The weld altered from X-shape to Y-shape with the increased thickness of Ni foil. During welding, Al-Si coating was melted and diluted into the welding pool, forming δ-ferrite (a rich-Al phase with low toughness and strength) in FZ and FB. This phase deteriorated the strength of the joints. After adding Ni, the amount and size of the δ-ferrite phase decreased. With a significant thickness of Ni foil, δ-ferrite would disappear. However, a new phase (FM, rich-Ni phase) probably formed except PM(a no or negligible Ni phase). The heat-affected zone (HAZ) on the side of 22MnB5 comprised a coarse martensite zone, refined martensite zone, martensite+ferrite zone, and tempered martensite zone from the FZ to the basic material. HAZ on the side of galvanized steel mainly contained ferrite and pearlite. After adding Ni foil, the strength of the joint was more than that without Ni. The maximum strength of the joint can be up to 679MPa because of the disappearance of δ-ferrite. Meanwhile, the toughness of the joint increased. The fracture mode was from three mixed fractures(cleavage, quasi-cleavage, and dimple) to one fracture(dimple).
Keywords
Laser welding; Al-Si coated hot stamping steel; Galvanized steel; Microstructure; Mechanical properties; Ni foil
Subject
Chemistry and Materials Science, Metals, Alloys and Metallurgy
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
