Structural Integrity of Spot-Welds Used for Auto-Body Fabrication
The effects of weld nugget size, base metal strength, mode of loading and pre-strain of base metal on the load bearing capacity of spot-welds have been investigated using two varieties of interstitial free steel sheets. The effect of bake hardening treatment after spot-welding of prestrained sheets has also been examined using an ultra low carbon bake hardening grade steel. The major results infer that: (i) the load bearing capacity of spot-welds increases with increasing nugget size and base metal strength, (ii) the load bearing capacity of spot-welds increases with increasing pre-strain of base metal, (iii) the remnant dislocation density around the spot-weld increases with increasing pre-strain, (iv) the strength of spot-welds on pre-strained sheets does not alter significantly after the baking treatment, but baking treatment increases the strength of pre-strained base metals, and (v) the location of failure is commonly at the interface of HAZ/base metal for tensile-shear specimens and at the HAZ for cross-tension specimens.
M.S.J. Hashmi, S. Mridha and S. Naher
K. K. Ray and G. Mukhopadhyay, "Structural Integrity of Spot-Welds Used for Auto-Body Fabrication", Advanced Materials Research, Vols. 264-265, pp. 427-432, 2011