Figure Source Data Sets for: "Electrochemical and Tribological Performance of Hybrid 60 and AISI 52100 Bearing Steels in Water-Based Lubricants"

Data description – Figure 2: Open Circuit Potential (OCP) evolution This dataset contains time-resolved open circuit potential (OCP) measurements for AISI 52100 and Hybrid 60 bearing steels immersed in a water-based lubricant. The data record the evolution of OCP over a 12-hour period under hydrodynamic conditions at room temperature. OCP values are reported as a function of immersion time, starting immediately after the electrode was submerged in the lubricant. The measurements capture the transient electrochemical stabilization of both steels and reflect the development of surface films and changes in electrochemical activity over time. Units: Time, hours (h) Open circuit potential, volts vs. Ag/AgCl (V) Data description – Figure 3: Potentiodynamic (Tafel) polarization data This dataset contains potentiodynamic polarization measurements obtained for AISI 52100 and Hybrid 60 bearing steels in a water-based lubricant. The data include polarization curves recorded under both stagnant conditions (0 rpm) and hydrodynamic conditions (2300 rpm), as well as measurements performed at different temperatures (25 °C and 40 °C). The dataset consists of electrode potential values (referenced to Ag/AgCl) as a function of logarithmic current density. Units: Electrode potential, volts vs. Ag/AgCl (V) Current density, microamperes per square centimeter (µA/cm²) Data description – Figure 6: Friction coefficient versus time This dataset contains friction coefficient measurements obtained on a ball-on-disc tribological tests for AISI 52100 and Hybrid 60 bearing steels lubricated with a water-based lubricant. The tests were conducted using a Mini Traction Machine (MTM) under a constant normal load corresponding to a maximum Hertzian contact pressure of approximately 1.2 GPa and at a lubricant temperature of 40 °C. The friction coefficient was recorded over a total test duration of 12 hours. Units:Time, hours (h)Friction coefficient, dimensionless (–)