Heat Treatment to Improve Fatigue Strength of Ti-3Al-8V-6Cr-4Mo-4Zr Titanium Alloy

摘要

In the present invention, high durability (fatigue limit / tensile strength) by improving the fatigue strength of the titanium alloy of β-C type Ti-3Al-8V-6Cr-4Mo-4Zr, which is expected to be applied to high-performance driving parts due to excellent cold workability. ), A heat treatment method was obtained.;In the case of general steel, fatigue limit (fatigue strength) increases or decreases in proportion to mechanical strength such as tensile strength and hardness, but in the present Ti-3Al-8V-6Cr-4Mo-4Zr titanium alloy, The phenomenon is not applied.;Therefore, in the present invention, unlike the heat treatment conditions generally recommended by the engineering data or the manufacturer for the Ti-3Al-8V-6Cr-4Mo-4Zr titanium alloy, 700 ℃ (675 ~ 725 ℃ much lower than the transformation point 793 ℃) Solution is maintained by air cooling after 30 ~ 60 minutes in quenching, and aging treatment is carried out by aging treatment by air cooling after holding at 510 ~ 550 ℃ for 10 ~ 20 hours to maximize fatigue limit (fatigue limit / tensile strength). Improved to about 0.589.