LAUSR

Abstract The microstructure and corrosion behavior of the hot-rolled Ti-30Zr-5Al-3V-xFe alloys were investigated. All the alloys are composed of α and β phases. With the increase of Fe content, α laths gradually decreases and the relative content of β phase increases. Potentiodynamic polarization curves recorded in 3.5% NaCl and 5% HCl solutions show that all the alloys exhibit a passivation behavior at potential in the range of 0.25–1.25 V (SCE). An evident change in corrosion current density is presented for all of the alloys in both solutions, which can be attributed to the passive film breakdown caused by pitting corrosion. All the alloys exhibit more positive pitting potential compared with the typical 304 stainless steel. The impedance spectra were fitted using equivalent circuit with two time constants. The alloys with different Fe contents exhibit capacitive behavior with phase angles closed to −80° and high impedance values at low frequency. Containing Fe alloys exhibit commendable combination of mechanical properties and corrosion resistance, which is markedly superior to the typical 304 stainless steel although the corrosion resistance decreases by the addition of Fe. The relative content of α and β phases and the segregations of Fe and V elements are identified as the main factors that affect the corrosion resistance of the hot-rolled alloys.