Assessment of stress corrosion crack initiation and propagation in AISI type 316 stainless steel by electrochemical noise technique

Electrochemical noise (EN) analyses, using time domain, frequency domain and statistical parameters, were carried out on the potential and current data obtained on AISI type 316 stainless steel during (i) pitting corrosion in deaerated 0.5 M sodium chloride (NaCl) solution, and during (ii) stress corrosion cracking (SCC) in boiling acidified NaCl solution. Visual records and statistical analysis of the current and potential data alongwith the spectral estimation using maximum entropy method (MEM) gave useful informations on differentiating between these corrosion processes and on the effect of stress in accelerating pitting corrosion. The results correlated well with the optical microscopic observations.