ASTM B381 Grade 2 and Grade 5 Titanium Flanges Long Weld Neck
Flange Raised Face Titanium for Piping and Industrial Applications
Chemical Composition of Titanium Pipe Flanges:
Here's the detailed chemical composition of the two commonly used
titanium grades, Grade 2 and Grade 5, in the context of titanium
pipe flanges:
| Grade | Ti (min) | C (max) | Fe (max) | H (max) | O (max) | Al (min) | V (min) |
|---|
| Grade 2 | 99.2% | 0.1% | 0.3% | 0.015% | 0.03% | 0.25% | - |
| Grade 5 | 90% | - | 0.25% | - | - | 6% | 4% |
Grade 2 (Commercially Pure Titanium) has a high purity level of
titanium, with only minimal amounts of carbon, iron, hydrogen, and
oxygen. It is an unalloyed titanium grade and is widely used in
general industrial applications.
Grade 5 (Ti-6Al-4V) contains a mixture of titanium, aluminum, and
vanadium. This alloy offers significantly higher strength and
improved performance compared to Grade 2, making it ideal for
aerospace, marine, and high-performance applications.
Mechanical Properties of ASTM B381 Titanium Plate Flanges:
The mechanical properties of titanium alloys are crucial when
choosing materials for flanges, as they determine the material's
strength, performance under pressure, and durability. Below are the
properties of Titanium Grade 2 and Titanium Grade 5:
| Element | Titanium Grade 2 | Titanium Grade 5 |
|---|
| Density | 4.5 g/cm³ | 4.43 g/cm³ |
| Melting Point | 1665°C (3030°F) | 1632°C (2970°F) |
| Tensile Strength | Psi – 49,900 (MPa – 344) | Psi – 138,000 (MPa – 950) |
| Yield Strength (0.2% Offset) | Psi – 39,900 (MPa – 275) | Psi – 128,000 (MPa – 880) |
| Elongation | 20% | 14% |
Key Differences in Mechanical Properties:
Density: Grade 2 is slightly denser than Grade 5, but the
difference is minimal and generally not a significant factor in
most applications.
Melting Point: Grade 2 has a slightly higher melting point than
Grade 5, which indicates its ability to withstand slightly higher
temperatures before melting.
Tensile Strength: Grade 5 has significantly higher tensile strength
(138,000 psi or 950 MPa) compared to Grade 2 (49,900 psi or 344
MPa). This makes Grade 5 much more suitable for high-stress
applications.
Yield Strength: Grade 5 also has higher yield strength (128,000 psi
or 880 MPa), which is important for maintaining structural
integrity under load, especially in aerospace and military
applications.
Elongation: Grade 2 has a higher elongation (20%) compared to Grade
5 (14%), meaning Grade 2 is more ductile and can stretch more
before breaking, which is valuable in forming processes.
Comparing Titanium Grades for Long Weld Neck Flanges:
| Feature | Grade 7 (Ti-0.15Pd) | Grade 9 (Ti-3Al-2.5V) | Grade 11 (Ti-0.3Mo-0.8Ni) |
|---|
| Primary Alloying Elements | 0.15% Palladium | 3% Aluminum, 2.5% Vanadium | 0.3% Molybdenum, 0.8% Nickel |
| Corrosion Resistance | Excellent, particularly for acids and chlorides | Good, especially in marine environments | Excellent in both acidic and high-temperature environments |
| Strength | Moderate strength | High strength-to-weight ratio | Good strength with high-temperature resistance |
| Weldability | Good | Excellent, easy to weld | Good, particularly in high-temperature applications |
| Applications | Chemical processing, marine, aerospace | Aerospace, military, marine, chemical processing | Chemical processing, power generation, aerospace |
| Temperature Resistance | Moderate | Moderate | Excellent, especially in high temperatures |
Conclusion:
- Titanium Grade 7 Long Weld Neck Flanges are ideal for corrosive
environments, especially those involving acids and chemicals.
They're commonly used in chemical processing, marine, and aerospace
applications.
- Titanium Grade 9 Long Weld Neck Flanges are perfect for
applications requiring a high strength-to-weight ratio, such as in
aerospace, military, and marine environments. They provide
excellent durability and reliability under stress.
- Titanium Grade 11 Long Weld Neck Flanges excel in high-temperature
applications where oxidation resistance is a must. They're commonly
used in power generation, chemical processing, and aerospace
industries, particularly in environments subject to elevated
temperatures.
Each of these titanium alloys offers distinct advantages, and
selecting the right material depends on the specific demands of the
application, including factors such as corrosion resistance,
strength, temperature tolerance, and weldability.
