Effects of agitation on the tribo-electrochemical behavior of AISI 304 stainless steel in sulfuric acid

Purpose This study aims to systematically investigate the tribo-electrochemical behavior of AISI 304 stainless steel in sulfuric acid, focusing on the influence of mechanical agitation during tribocorrosion on mass transport and reaction kinetics within the passive system, as well as the resulting mechanisms affecting electrode processes. Design/methodology/approach The study combines potentiostatic and potentiodynamic polarization tests with intermittent sliding experiments under controlled load and frequency. Current transient analysis was used to examine the effect of mechanical agitation on mass transport-related electrode processes, and Auger electron spectroscopy (AES) was used to investigate the properties and dissolution behavior of the passive film under mechanical stirring. Findings By applying potentials in passivation transition and passive regions, increased frictional load shifts the transient current from negative to positive. This corresponds to a mechanistic change from cathodic hydrogen evolution reaction (HER) dominance at low loads to anodic dissolution controlled by depassivation at high loads. Mechanical agitation enhances HER kinetics by improving mass transfer and promotes passive film dissolution through synergistic interaction with aggressive anions, thereby significantly altering anodic reaction kinetics. Current transient analysis and AES depth profiling confirm that mechanical agitation inhibits stable film growth and accelerates its dissolution. Originality/value This work provides new insights into the dual role of HER in simultaneously influencing cathodic and anodic processes during tribocorrosion. It establishes a mechanistic link between mechanical agitation, mass transfer enhancement and altered electrode kinetics in passive systems, offering a theoretical basis for understanding degradation mechanisms during tribocorrosion of stainless steel in acidic environments.