Titanium Grade 11 is a commercially pure (CP) alpha titanium alloy, essentially Grade 1 titanium with a small palladium addition (≈0.12–0.25%). This palladium-enhanced composition dramatically improves resistance to crevice corrosion, pitting, and acid attack while retaining excellent ductility and formability.
Material Classification
| Property | Details |
|---|---|
| UNS | R52250 |
| Type | Alpha titanium alloy (CP + Pd) |
| Heat Treatable | No |
| Primary Feature | Exceptional corrosion resistance |
Metallurgical Behavior
Titanium Grade 11 has a single-phase alpha (HCP) structure. It is strengthened only by cold working and is not heat treatable. The palladium addition stabilizes and enhances the protective TiO₂ oxide layer, improving corrosion resistance without reducing ductility.
✔ Excellent weldability (no post-weld heat treatment)
✔ Outstanding formability, rolling, bending, and deep drawing
✔ Stable microstructure in aggressive environments
Corrosion Resistance
Grade 11 is selected primarily for extreme corrosion resistance, often outperforming Grade 2 titanium in aggressive environments.
Resistant to:
✔ Chlorides and seawater
✔ Sulfuric acid (low to moderate concentration)
✔ Hydrochloric acid (controlled conditions)
✔ Wet chlorine gas
✔ Acidic chemical process streams
✔ Crevice and pitting corrosion
Typical Applications
Chemical & Process Industries
Heat exchangers, condensers, reactors, piping, acid handling equipment
Marine & Offshore
Seawater piping, desalination plants, offshore heat exchangers
Power & Energy
Flue gas desulfurization (FGD) systems, cooling systems
Medical & Biochemical
Pharmaceutical and biotech processing equipment
Oil & Gas
Downhole tubing and chemical injection systems
Advantages of Titanium Grade 11
✔ Near Grade 7 corrosion resistance at lower cost
✔ Excellent weldability and fabrication ease
✔ Long service life with minimal maintenance
✔ Lightweight (~45% lighter than steel)
✔ Biocompatible and non-toxic
Limitations
⚠ Lower strength than structural titanium alloys
⚠ Higher cost than Grade 2 due to palladium
⚠ Not suitable for high-load structural applications
Why Choose Titanium Grade 11?
Choose Titanium Grade 11 when corrosion resistance is more critical than strength, especially in acidic, chloride, or marine environments. It is a cost-effective alternative to Grade 7 where extreme corrosion resistance is required with easier fabrication.
Grade Comparison (CP Titanium)
| Grade | Key Feature |
|---|---|
| Grade 1 | Highest ductility, lowest strength |
| Grade 2 | General-purpose corrosion resistance |
| Grade 11 | Palladium-enhanced corrosion resistance |
| Grade 7 | Maximum corrosion resistance (higher Pd) |
| Grade 12 | Higher strength, moderate corrosion resistance |
In summary:
Titanium Grade 11 is engineered for longevity, corrosion resistance,
and reliability in the harshest chemical and marine environments.