Atmospheric-Induced Stress Corrosion Cracking of Grade 2205 Duplex Stainless Steel-Effects of 475 degrees C Embrittlement and Process Orientation


Creative Commons License

Ornek C., Idris S. A. M. , Reccagni P., Engelberg D. L.

METALS, vol.6, no.7, 2016 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 6 Issue: 7
  • Publication Date: 2016
  • Doi Number: 10.3390/met6070167
  • Journal Name: METALS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Keywords: duplex stainless steel, 475 degrees C embrittlement, atmospheric-induced stress corrosion cracking, electron backscatter diffraction, X-ray diffraction, residual stress, SWIMMING POOLS ATMOSPHERES, CHLORIDE-INDUCED CORROSION, PITTING CORROSION, INITIAL-STAGE, BEHAVIOR, TEMPERATURE, SUSCEPTIBILITY, FERRITE, 304-STAINLESS-STEEL, MICROSTRUCTURE
  • Istanbul Technical University Affiliated: No

Abstract

The effect of 475 degrees C embrittlement and microstructure process orientation on atmospheric-induced stress corrosion cracking (AISCC) of grade 2205 duplex stainless steel has been investigated. AISCC tests were carried out under salt-laden, chloride-containing deposits, on U-bend samples manufactured in rolling (RD) and transverse directions (TD). The occurrence of selective corrosion and stress corrosion cracking was observed, with samples in TD displaying higher propensity towards AISCC. Strains and tensile stresses were observed in both ferrite and austenite, with similar magnitudes in TD, whereas, larger strains and stresses in austenite in RD. The occurrence of 475 degrees C embrittlement was related to microstructural changes in the ferrite. Exposure to 475 degrees C heat treatment for 5 to 10 h resulted in better AISCC resistance, with spinodal decomposition believed to enhance the corrosion properties of the ferrite. The austenite was more susceptible to ageing treatments up to 50 h, with the ferrite becoming more susceptible with ageing in excess of 50 h. Increased susceptibility of the ferrite may be related to the formation of additional precipitates, such as R-phase. The implications of heat treatment at 475 degrees C and the effect of process orientation are discussed in light of microstructure development and propensity to AISCC.