The load bearing capacity (LBC), often referred to as strength, of spot-welded joints on as-received and pre-strained sheets of an interstitial free (IF) steel has been examined under 3.5% sodium chloride solution using tensile-shear (TS) specimens. These tests have been carried out under three different test conditions: (i) after immersing the samples in the solution for various duration of time, (ii) at various slow strain rates by keeping the samples in solution, and (iii) at slow strain rate under in situ hydrogen charging. Analyses of the results infer that (i) increased duration of immersion of the samples in aggressive environment decreases their LBC but increases their extension corresponding to the maximum load (EML), (ii) slow strain rate tests in the solution indicate marginal decrease of LBC and EML of the spot-welds, (iii) the LBC and EML of the spot-welds of pre-strained sheets decrease considerably with cathodic hydrogen charging while EML of the spot-welded joints on the as-received sheets is found to improve, and finally, (iv) the detrimental effect of corrosive environment increases with increased pre-strain of the investigated sheets. These observations have been discussed together with post-failure examinations of the broken fractured surfaces, which have assisted in understanding their failure mechanism.
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