Publication detail

Microstructural Characterization of Laser Weld of Hot-Stamped Al-Si Coated 22MnB5 and Modification of Weld Properties by Hybrid Welding

ŠEBESTOVÁ, H. HORNÍK, P. MIKMEKOVÁ, Š. MRŇA, L. DOLEŽAL, P. NOVOTNÝ, J.

Original Title

Microstructural Characterization of Laser Weld of Hot-Stamped Al-Si Coated 22MnB5 and Modification of Weld Properties by Hybrid Welding

Type

journal article in Web of Science

Language

English

Original Abstract

The presence of Al-Si coating on 22MnB5 leads to the formation of large ferritic bands in the dominantly martensitic microstructure of butt laser welds. Rapid cooling of laser weld metal is responsible for insufficient diffusion of coating elements into the steel and incomplete homogenization of weld fusion zone. The Al-rich regions promote the formation of ferritic solid solution. Soft ferritic bands cause weld joint weakening. Laser welds reached only 64% of base metal's ultimate tensile strength, and they always fractured in the fusion zone during the tensile tests. We implemented hybrid laser-TIG welding technology to reduce weld cooling rate by the addition of heat of the arc. The effect of arc current on weld microstructure and mechanical properties was investigated. Thanks to the slower cooling, the large ferritic bands were eliminated. The hybrid welds reached greater ultimate tensile strength compared to laser welds. The location of the fracture moved from the fusion zone to a tempered heat-affected zone characterized by a drop in microhardness. The minimum of microhardness was independent of heat input in this region.

Keywords

22MnB5; laser welding; hybrid welding; cooling rate; tensile strength; microstructure; microhardness

Authors

ŠEBESTOVÁ, H.; HORNÍK, P.; MIKMEKOVÁ, Š.; MRŇA, L.; DOLEŽAL, P.; NOVOTNÝ, J.

Released

14. 7. 2021

Publisher

MDPI

Location

BASEL

ISBN

1996-1944

Periodical

Materials

Year of study

14

Number

14

State

Swiss Confederation

Pages from

1

Pages to

15

Pages count

15

URL

https://doi.org/10.3390/ma14143943

Full text in the Digital Library

http://hdl.handle.net/11012/204054

BibTex

@article{BUT177302,
  author="Hana {Šebestová} and Petr {Horník} and Šárka {Mikmeková} and Libor {Mrňa} and Pavel {Doležal} and Jan {Novotný}",
  title="Microstructural Characterization of Laser Weld of Hot-Stamped Al-Si Coated 22MnB5 and Modification of Weld Properties by Hybrid Welding",
  journal="Materials",
  year="2021",
  volume="14",
  number="14",
  pages="1--15",
  doi="10.3390/ma14143943",
  issn="1996-1944",
  url="https://doi.org/10.3390/ma14143943"
}