A novel model based on asperities contact for the assessment of tribocorrosive wear in marine applications

Tribocorrosion refers to a degradation mechanism resulting from the synergistic interaction between mechanical wear and corrosion, acting positively or negatively (antagonism). It is a widespread phenomenon across several sectors—such as marine, automotive, nuclear and biomedical—due to its substantial impact on equipment in terms of failures, downtime, and maintenance costs. To date, common methods to investigate tribocorrosive phenomena include experimental techniques (e.g., voltammetry, spectroscopy) and analytical models. However, most of them consider the macroscopic scale and do not include the kinetics of repassivation. This study proposes a novel approach based on Greenwood–Williamson (GW) theory to estimate tribocorrosive material loss, by considering surface asperities and a dynamic changes of the surface topography after each sliding cycle. For validation, experiments were conducted using AISI 316L stainless steel–alumina tribosystem immersed in a 3.8% NaCl artificial seawater solution (pH 8.2), tested under three different sliding frequencies. The experimental setup involved an in-situ reciprocating tribometer coupled with a potentiostat and an optical confocal/interferometric microscope. Results indicate that sliding speed significantly influenced the tribocorrosive response, and the proposed model demonstrated a good agreement with experimental findings.