Welding metallurgy of duplex stainless steel during resistance spot welding

Arabi, S. H ; Sharif University of Technology

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  1. Type of Document: Article
  2. Abstract:
  3. This paper investigates the metallurgical and mechanical response of 2304 duplex stainless steel-as an interesting candidate for automotive body-in-white applications-to resistance spot welding. The results showed the high cooling rate associated with the resistance spot welding process suppressed the postsolidification ferrite-austenite transformation leading to improper ferrite-austenite phase balance with a reduced volume fraction of austenite and consequent precipitation of chromium-rich nitrides. The effects of welding current, as the key parameter determining the weld heat input, on the austenite volume fraction and precipitation are discussed. The minimum fusion zone hardness corresponding to the highest austenite volume fraction and minimum volume fraction of nitrides was obtained when the cooling rate was the lowest. The failure mode transition, peak load, and energy absorption of the welds were investigated. It was found that the fusion zone size is the key factor controlling peak load and energy absorption of the welds. Mechanical properties of the duplex stainless steel spot welds were compared with those of other automotive steels
  4. Keywords:
  5. Phase transformations ; Austenite ; Cooling ; Electric welding ; Energy absorption ; Ferrite ; Metallurgy ; Nitrides ; Phase transitions ; Resistance welding ; Spot welding ; Steel metallurgy ; Volume fraction ; Welding ; Welds ; Austenite transformations ; Austenite volume fraction ; Duplex stainless steel ; Failure mode transition ; Mechanical performance ; Mechanical response ; Phase balance ; Resistance spot welding ; Stainless steel
  6. Source: Welding Journal ; Volume 96, Issue 9 , 2017 , Pages 307s-318s ; 00432296 (ISSN)
  7. URL: http://weldingsource.org/welding-metallurgy-duplex-stainless-steel-resistance-spot-welding