Corrosion Behavior Of TC2 Titanium Alloy Under Stress And Strain In Simulated Seawater Environment

Corrosion behavior of TC2 titanium alloy under stress and strain in simulated seawater environment

The surface electrochemical and corrosion behavior of TC2 titanium alloy in simulated seawater and the effect of different deformation on it were studied.Methods u-shaped sample was prepared and simulated seawater immersion test was carried out. Potential test, ac impedance and polarization curve test, scanning electron microscopy (SEM), X-ray diffraction (XRD) and other methods were used for analysis.Results during the 240-d simulated seawater immersion test, the surface passivation film impedance of the intangible TC2 titanium alloy increased rapidly at first, then slowly, and the corrosion potential continued to increase, so the surface electrochemical reaction decreased and the corrosion rate was low.45 ° deformation of TC2 titanium alloy specimen surface passivation membrane impedance value to rise slightly, after the fall, is lower than the initial impedance value finally.90 ° deformation sample surface passivation membrane impedance values continue to fall.After 240 d after soaking, invisible change of the surface of the sample appear tiny pitting, 45 ° deformation sample surface pitting density increases, the 90 ° deformation cracks on sample surface vertical compressive stress direction.XRD results show that the increase of Ca2+ and Mg2+ plasma adsorption at the deformation may be related to the increase of surface roughness and surface activity of TC2 titanium alloy.Conclusion in the simulated seawater environment, the non-strain specimen has a strong corrosion resistance, and the strain leads to the surface passivation film rupture, pitting corrosion increase and even crack on TC2 titanium alloy, which increases the stress corrosion sensitivity of TC2 titanium alloy.