Experimental and modelling study of the effect of tempering on the susceptibility to environment-assisted cracking of AISI 420 martensitic stainless steel

Anantha K. H., Ornek C., Ejnermark S., Thuvander A., Medvedeva A., Sjostrom J., ...More

CORROSION SCIENCE, vol.148, pp.83-93, 2019 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 148
  • Publication Date: 2019
  • Doi Number: 10.1016/j.corsci.2018.12.010
  • Journal Name: CORROSION SCIENCE
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.83-93
  • Keywords: Martensitic stainless steel, Residual stress, Tempering, Environment-assisted cracking, Pit-to-crack transition, STRESS-CORROSION CRACKING, PITTING CORROSION, MICROSTRUCTURE, TEMPERATURE, STRENGTH, PROPAGATION, PIT
  • Istanbul Technical University Affiliated: No

Abstract

The resistance to environment-assisted cracking (EAC) of AISI 420 martensitic stainless steel (MSS) was investigated in 0.3 M NaCl solution (room temperature) at constant loads for 30 days. The steel tempered at 250 degrees C was superior to the 500 degrees C-temper, which showed corrosion pits favouring cracking. The fracture surface showed faceted grains, cleavage, striations, and inter- and transgranular cracks, suggesting a mixed stress corrosion cracking (SCC) and hydrogen embrittlement (HE) mechanism as the cause for EAC. Finite element modelling (FEM) indicated strain/stress localization at the mouth of deep pits and at the wall of shallow pits, displaying the favoured locations for pit-to-crack transition.