Effects of Zr and Fe additions on corrosion resistance and deformation mode in Ti-15Mo alloy(J001_6)

摘要

In the last meeting [1], we reported that a yield strength of 440MPa in the Ti-15Mo alloy (mass%) isimproved to 840MPa by 1 mass% Fe addition, and this increase in the yield strength is attributed to the change in thedeformation mode of the β phase from {332}<113> twinning to slip. On the other hand, the Ti-15Mo-1Fe alloy exhibitsan inferior crevice corrosion resistance in seawater at 373K due to a decrease in the bond order (Bo). These resultssuggest that an increasing in the Bo by the β stabilizing element addition is an effective method to improve thecorrosion resistance in addition to the yield strength. Among the alloying elements, Zr is a promising alloying elementfor improving the corrosion resistance since the Bo increases by Zr addition in the Ti-15Mo alloy. However, Zr has alow ability to stabilize the β phase. The purpose of this study is to investigate the effects of Zr and Fe additions on thecrevice corrosion resistance in seawater at 373K and the tensile deformation mode at ambient temperature.