Working Paper Article Version 1 This version is not peer-reviewed

Microstructure and Mechanical Properties of Laser-welded DP Steels Used in the Automotive Industry

Version 1 : Received: 30 December 2020 / Approved: 31 December 2020 / Online: 31 December 2020 (12:49:00 CET)

A peer-reviewed article of this Preprint also exists.

He, H.; Forouzan, F.; Volpp, J.; Robertson, S.M.; Vuorinen, E. Microstructure and Mechanical Properties of Laser-Welded DP Steels Used in the Automotive Industry. Materials 2021, 14, 456. He, H.; Forouzan, F.; Volpp, J.; Robertson, S.M.; Vuorinen, E. Microstructure and Mechanical Properties of Laser-Welded DP Steels Used in the Automotive Industry. Materials 2021, 14, 456.

Journal reference: Materials 2021, 14, 456
DOI: 10.3390/ma14020456

Abstract

The aim of this work was to investigate the microstructure and the mechanical properties of la-ser-welded joints combined of DP800 and DP1000 high strength thin steel sheets. The welded joints (WJ) comprised of similar/dissimilar steels with similar/dissimilar thickness were consisted of different zones and exhibited similar microstructural characteristics. The trend of microhard-ness for all WJs was consistent, characterized of the highest value at hardening zone (HZ) and lowest at softening zone (SZ). The degree of softening was more severe and the size of SZ was wider in the WJ combinations of DP1000 than DP800. The tensile test fractures were located at the base material (BM) for all DP800 weldments, while the fractures occurred at the fusion zone (FZ) for the weldments with DP1000 and those with dissimilar sheet thicknesses. The DP800-DP1000 weldment presented similar yield strength (YS) and ultimate tensile strength (UTS) values but lower elongation (EI) in comparison with the DP800-DP800 weldment, which showed similar strength properties as the BM of DP800. However, the EI of DP1000-DP1000 weldment was much lower in comparison with the BM of DP1000. The DP800-DP1000 weldment with dissimilar thicknesses showed the highest YS and UTS values compared with the other weldments, but with the lowest EI. The fatigue fractures occurred at the WJ for all types of weldments. The DP800-DP800 weldment had the highest fatigue limit and DP800-DP1000 with dissimilar thick-nesses had the lowest fatigue limit. The fatigue crack initiated from the weld surface.

Subject Areas

Laser welding; Dual phase steel; Similar/dissimilar welded joints; Microhardness; Tensile properties; Fatigue

Comments (0)

We encourage comments and feedback from a broad range of readers. See criteria for comments and our diversity statement.

Leave a public comment
Send a private comment to the author(s)
Views 0
Downloads 0
Comments 0
Metrics 0


×
Alerts
Notify me about updates to this article or when a peer-reviewed version is published.
We use cookies on our website to ensure you get the best experience.
Read more about our cookies here.