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Welding in the World

, Volume 63, Issue 1, pp 87–95 | Cite as

Investigations on the impact and fracture toughness of beam welded structural steels with yield strengths from 355 to 960 MPa

  • Ann-Christin HesseEmail author
  • Thomas Nitschke-Pagel
  • Klaus Dilger
Research Paper
  • 83 Downloads

Abstract

Beam welding processes, i.e., laser beam welding and electron beam welding, are increasingly used to join structural steels. Welds which originate from these joining processes are known for having high weld hardness, and, in many cases, a martensitic or martensitic-bainitic microstructure in the weld seam. As these characteristics might affect the toughness behavior of those joints compared to arc welded joints, the toughness of beam-welded fine-grained steels has been investigated. Charpy impact toughness temperature curves as well as fracture mechanics tests were carried out to find a suitable T0-T28J-correlation. The results showed that the T0-T28J-correlation which is commonly used for the assessment of arc welded joints in EN 1993-1-10 does not lead to conservative results. A correlation which was originally proposed for low-carbon ultra-high-strength quenched steels was found to be more suitable.

Keywords

Laser welding EB welding Brittle fracture Fine grained steels Fracture toughness Impact toughness Transition temperature 

Abbreviations

CIP

Crack in plane

CO2-LB

CO2-laser beam welded

CPD

Crack path deviation

EB

Electron beam welded

EPUL

Energy per unit length

SE(B)

Single-edged bend specimen

SS-LB

Solid state laser beam welded

Nomenclature

CV-US

Upper shelf Charpy impact energy

EPUL

Energy per unit length

HV

Vickers hardness

SE(B)

Single-edged bend specimen

σ

Standard deviation

σYS

Yield strength

T0

Fracture toughness reference temperature

T28J

Impact toughness transition temperature

T0-SE(B)

T0-temperature for SE(B) specimen

Notes

Acknowledgements

Special thanks to the pro beam AG & Co. KgaA and TRUMPF GmbH + Co. KG for carrying out the welding work and the preparation of components.

Funding information

We would like to thank the German Federation of Industrial Research Associations (AiF) for its financial support of the research project IGF-No. 18.174 N. This project was carried out under the auspices of AiF and financed within the budget of the German Federal Ministry of Economics and Technology (BMWi) through the program to promote joint industrial research and development (IGF).

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Copyright information

© International Institute of Welding 2018

Authors and Affiliations

  1. 1.Institute of Joining and WeldingTechnische Universität BraunschweigBraunschweigGermany

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