Weld Associated Localized Necking in Various Steels

The joining of metals by welding results in unavoidable heating of adjacent material causing the formation of a weld heat affected zone (HAZ). Deformation of the weld zone as during automotive wheel rim fabrication is reported to develop a non-uniform strain distribution in the weld HAZ of high strength steels. This can lead to the formation of a localized neck in the HAZ and hence, a higher production scrap rate in these steels compared to plain carbon steel.

This report examines the mechanical property changes that occur in the weld HAZ of three commercial high strength steels and a plain carbon steel. These mechanical property changes are explained in terms of the phase transformations that occur on heating the steels during welding, and the explanations provide insight into potential solutions for reducing the tendency for post-weld, deformation-induced necking during automotive rim fabrication.