Speaker
Description
Liquid Metal Embrittlement (LME) is a complex phenomenon which may occur during spot welding of zinc-coated Advanced High Strength Steels (AHSS) developed for the Automotive market.
Zinc or zinc alloy in liquid state penetrates along the steel grain boundaries and may cause, depending on conditions, grains’ decohesion and cracks’ initiation and propagation under given mechanical stresses.
LME sensitivity depends on the steel mechanical properties and surface / sub-surface characteristics, the coating composition and microstructure and the spot welding process itself.
In this study, a comparative assessment of conventional GalvanIzed (GI) and GalvAnnealed (GA) coatings in terms of LME behavior has been done on the same sensitive AHSS material with the same welding process configuration and parameters. The intrinsic effect of the type of coating (GI vs GA) on the LME performance could therefore be properly evaluated.
Keywords
Automotive, GalvanIzed (GI), GalvAnnealed (GA), Liquid Metal Embrittlement (LME), spot welding, zinc-coated Advanced High Strength Steels (AHSS)