High temperature performance of Gr5 titanium rod (Ti-6Al-4V) in ASTM B348

1. ‌ high temperature operating temperature range ‌

‌ long-term use temperature ‌ : ≤400℃, can work stably and maintain mechanical properties and oxidation resistance ‌.

‌ Short-term tolerable temperature ‌ : up to 550℃, but need to avoid severe oxidation or high stress environment ‌.

2. ‌ high temperature mechanical properties ‌

‌ Strength and stability ‌ :

The tensile strength at 400℃ can still maintain about ‌600-800 MPa‌, which is better than that of most structural steels ‌.

High temperature creep performance is excellent, suitable for long-term bearing parts (such as aircraft engine compressor disc) ‌.

‌ Heat treatment effect ‌ :

The microstructure is stable in annealed state (700-800℃), suitable for high temperature conditions; Solution aging (850-950℃) can improve the strength, but the hardenability is poor (cross-section ≤25mm) ‌.

3. ‌ high temperature oxidation behavior ‌

‌ oxide film protection ‌ :

Below 400℃, dense ‌TiO₂ oxide film ‌ is formed on the surface, effectively isolating oxygen and corrosive medium, and the oxidation weight gain rate is very low ‌.

The oxide film may be partially broken when the temperature exceeds 400℃, and the protection should be enhanced by surface coatings (such as ceramic coatings) ‌.

4. ‌ typical high temperature application scenario ‌

‌ aerospace ‌ : used for engine fan blades, compressor disks and high temperature fasteners, replacing steel parts can reduce the weight by 30%‌.

‌ Energy and Chemical Industry ‌ : For the manufacture of heat exchangers, high-temperature pipelines and steam system components for nuclear power plants, resistant to high-temperature steam and weakly corrosive media ‌.

5. ‌ high temperature performance limitation ‌

‌ Microstructure sensitivity ‌ : long-term exposure above 400℃ may lead to α phase coarsening and reduce plasticity and fatigue strength ‌.

‌ oxidation environment limitation ‌ : in molten salt or oxygen-rich high-temperature gas (such as oxygen flow >550℃) is prone to violent oxidation, need to cooperate with protective measures ‌.