![]() ![]() Additionally, the cleavage-dissolution model proposes that crack nucleation and propagation stages of SCC are governed by the synergistic effect of brittle rupture of low-surface-energy cleavage planes in conjunction with anodic dissolution 6. Several mechanisms have been proposed to describe Cl ‒‒SCC phenomena, including the slip-dissolution model by Newman, where both crack nucleation and propagation are promoted by the dissolution of slip planes, as well as surface film cracking on newly developed fresh planes 4, 5. One of the most common causes of SCC for austenitic stainless steel is chloride-induced stress corrosion cracking (Cl ‒‒SCC), that develops as transgranular SCC (TG‒SCC) which is triggered when a critical chloride threshold is reached in the presence of residual and/or applied loading. Austenitic stainless steels, while used in many industries for outstanding corrosion resistance, are not immune to SCC, even under atmospheric conditions and ambient temperatures 3. ![]() SCC can develop without significant signs of damage accumulation, and is therefore critical threat for engineering asset management 1, 2. Stress corrosion cracking (SCC) occurs in the presence of a corrosive environment and mechanical stimulus, leading to the development of cracks that can propagate and reduce service lifetimes. Strain-induced martensitic transformation was associated with the brittle failure of AISI 316LN stainless steel, where α’–martensite phase preferentially incubated the pit, and favored crack nucleation, thus promoting pit-to-crack transition. Crack nucleation at lath martensite developed transgranular SCC. EIS analysis was corroborated by assessment of repassivation rates and pit growth, in addition to calculating \(\). The pit-to-crack transition was developed once the maximum θ value shifted from the low to high frequencies. The phase angle shift (Δφ) obtained by EIS at low frequencies was utilized to determine the pit-to-crack transition, differentiating from crack nucleation and propagation as identified by shifts in the frequency range of phase angle ( θ) peaks. ![]() The pit-to-crack transition of AISI 316LN stainless steel reinforcement exposed to stress corrosion cracking (SCC) in chlorides contaminated alkaline environment, was studied by a combination of slow strain rate testing (SSRT) and electrochemical impedance spectroscopy (EIS). ![]()
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