Joshua O. Atiba\(^1\)
\(^1\)Department of Mechanical Engineering, Bells University of Technology, P.M.B. 1015, Ota, Ogun State, Nigeria
Permanganate-based oxidizing steps are widely applied in nuclear chemical decontamination to oxidize chromium-rich oxides prior to reductive dissolution; however, the oxidizing-step pH strongly influences passive-film stability and substrate metal loss. This paper develops a quantitative process-window framework for 304L stainless steel exposed to 1 g/L KMnO\(_4\) solutions spanning acidic (HNO\(_3\)-adjusted) and alkaline (NaOH-adjusted) regimes. Using published mass-loss trends, polarization behavior, and SEM morphology as constraints, we formalize a corrosion–efficacy trade space and introduce a compact saturation-kinetics model for oxide removal on preoxidized 304L. A reanalysis of the reported alkaline cycling dataset at 0.4 g/L NaOH demonstrates rapid convergence of cumulative mass loss (0.161, 0.256, 0.351, 0.354, 0.358 mg/cm\(^2\) for cycles 1–5), consistent with finite oxide inventory removal followed by negligible incremental loss. We interpret the observed microspore morphology and subsequent reoxidation tendency as a surface-state consequence of porous residual structure that can accelerate oxide nucleation during post-treatment thermal exposure. The resulting process-window concept provides a practical basis for selecting oxidizing-step pH and minimum cycle count to achieve oxide removal while limiting corrosion allowance consumption.