FATIGUE DESIGN OF SPOT-WELDED AUSTENITIC AND DUPLEX STAINLESS SHEET STEELS |
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Authors: | J Linder A Melander M Larsson & Y Bergengren |
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Affiliation: | Swedish Institute for Metals Research, Drottning Kristinas väg 48, S-114 28 Stockholm, Sweden |
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Abstract: | The fatigue strength of spot-welded stainless sheet steels has been investigated. The main part of the fatigue tests was performed on a cold rolled austenitic stainless sheet steel (AISI304) in air at ambient temperature. For comparison, a duplex stainless steel (SAF2304) of similar yield strength as AISI304 was also incorporated into the test programme. Since the fatigue strength of spot-welded joints depends on the mode of loading, both shear-loaded and peel-loaded joints were tested. The fatigue strength of the spot-welded stainless steels was found to decrease with decreasing sheet thickness. Furthermore, the fatigue strength for peel-loaded joints is lower than that of shear-loaded joint for sheets of equal thickness. The local loading conditions at the weld edge have been analysed in terms of finite element calculations and fracture mechanics. A design parameter derived from a fracture mechanics analysis was defined for spot-welded stainless sheet steels. It was shown to predict the fatigue life of the present steels and joint configurations in a satisfactory way. |
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Keywords: | Fatigue Stainless steel Spot welds |
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