Figure - available from: Journal of Bio- and Tribo-Corrosion
This content is subject to copyright. Terms and conditions apply.
Source publication
Corrosion pit to crack transition behaviors of forged 304 Stainless steel were investigated in ferric chloride solution. The combined effect of corrosion and stresses were considered. The residual stresses were revealed by XRD analysis. As an outcome, the FESEM and EDX were used to analyze the surface morphology. The high-speed camera was used to d...
Similar publications
Laser shock peening Microstructure a b s t r a c t This paper investigates the post-processing of additively manufactured stainless steel (SS) 304 L samples through laser shock peening (LSP). Four samples, differently processed, (i) as-built (AB); (ii) as-built þ annealed; (iii) as-built þ polished; and (iv) as-built þ annealed þ polished, were use...
Citations
This work assesses the extent of localized corrosion of UNS S31603 (316L) in ammonium chloride solutions at low dissolved oxygen concentrations that could be a precursor to Stress Corrosion Cracking (SCC). The localized corrosion testing for UNS S31603 were conducted under de-aerated conditions with a maximum dissolved oxygen content of ~ 25 ppb in NH4Cl solutions of concentrations ranging from 5 wt.% to 40 wt.% (saturation) at temperatures of 65°C, 80°C and 95°C. Open-circuit potential transients were measured over a 48-72 hr. period under de-aerated conditions and Repassivation potentials of UNS S31603 were determined using Tsujikawa-Hisamatsu Electrochemical method based on ASTM G192 standard. It was seen that UNS S31603 is susceptible to pitting corrosion in NH4Cl solutions even under very low DO concentrations (~ 1 ppb) and were corroborated by pit-density and depth measurements through optical microscopy. The Galvele criteria of stable pits based on corrosion current agreed with measured pit-depths and repassivation abilities. The implications of pit size and shape on SCC propensity of UNS S31603 alloy due a thin film electrolyte formed under moist NH4Cl deposits have been discussed.
The damage to a metal is significantly enhanced when simultaneously exposed to a corrosive solution and a cyclic mechanical stress. However, decoupling the contributions from each damage mechanisms is difficult. Localized electrochemical techniques, in particular scanning electrochemical microscopy (SECM), scanning electrochemical cell microscopy (SECCM), scanning kelvin probe force microscopy (SKPFM), and scanning vibrating electrode technique (SVET), can be advantageous when determining corrosion fatigue damage mechanisms and local phenomena, such as the transition between a corrosion pit and a fatigue crack. The recent corrosion fatigue literature is reviewed to highlight the usefulness of each localized electrochemical technique and how they can contribute to advancing the corrosion fatigue field.
