FEM Modelling of Weld Damage in Continuous Cold Rolling of MIG/MAG Butt-Welded Stainless Steel Strips

Abstract:

Weld line fracture of butt-welded strips in stainless steel continuous rolling has been studied by numerical simulation using ForgeNxT®. The simulation plan includes weld line geometry as well as weld metal constitutive model parameters. The damage criterion used is the non-dimensional Latham & Cockroft function near the singular points of the weld line. Results are confronted to qualitative observations of fracture frequency and fracture initiation loci on the rolling line. Not surprisingly, the protrusion height of the weld line with respect to the strip top surface is found to be a major factor of risk. A second one pertains to the nature of the alloys used: due to the mushroom-like weld line cross-section geometry, damage at the top surface junction of the base metal and the weld metal becomes critical when the weld metal is harder than the base metal. Finally, on the rolling line investigated, prior to rolling properly speaking, the strip goes through a scale-breaking unit followed by acid pickling to eliminate oxides; the multiple, reverse plastic bending applied there contributes significantly to ductile damage, completing the explanation of why the fracture initiation locus is always found to be the same on the rolling line.

• Periodical: Key Engineering Materials (Volume 926)
• Pages: 569-579
• DOI: https://doi.org/10.4028/p-3b3cjo
• Online since: July 2022
• Authors: Leyne Demoulin, Zineb Zahar, Achraf El Mekkaoui, Arnaud Reignier, Katia Mocellin, Pierre Montmitonnet*, Pierre Emmanuel Leger
• Keywords: Butt-Welded Strips, FEM Modelling, Strip Rolling

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