Effect of Type-B liquid metal embrittlement cracks on high-cycle fatigue properties of spot-welded 1180 TRIP steel

Abstract

This study examines the effect of Type-B liquid metal embrittlement (LME) cracks on high-cycle fatigue resistance of a spot-welded plate of transformation-induced plasticity (TRIP) steel. Tensile shear and cross tension were employed to simulate a spot-welded component subjected to a complex state of stress. Interestingly, neither the existence nor the depth of Type-B LME cracks changed the high-cycle fatigue resistance of the spot-welded samples under the two deformation modes tested. The finite-element analysis revealed the formation of maximum local stress at the sample notch, which acted as a crack-initiation site. It should be noted that this site was not changed even upon adding a Type-B LME crack to the simulation model.

KEYWORDS:

• Liquid metal embrittlement
• TRIP steel
• high-cycle fatigue
• finite element method
• spot welding

Acknowledgements

The authors gratefully acknowledge the support from POSCO, which provided the materials and welding process for this research.

Disclosure statement

No potential conflict of interest was reported by the author(s).