Titanium Grade 2

When it comes to the world of titanium alloys, two of the most popular grades are Grade 2 and Grade 5. These two alloys are often compared regarding their strength, durability, and corrosion resistance. In this blog post, we will explore the differences between Grade 2 titanium and Grade 5 titanium to help you decide which alloy is the best for your specific use case.

 Chemical Composition Titanium Grade 2

ASTM Product Specifications

• B265 - Titanium and Titanium Alloy Strip, Sheet & Plate
• B381 - Titanium and Titanium Alloy Forgings
• B348 - Titanium and Titanium Alloy Bars and Billets
• B337  - Seamless and Welded Titanium and Titanium Alloy Pipe
• B338 - Seamless and Welded Titanium and Titanium Alloy Tubes for Condensers and Heat Exchangers
• B363 - Seamless and Welded Unalloyed Titanium and Titanium Alloy Welding Fittings
• B367 - Titanium and Titanium Alloy Castings

Applications of Titanium Grade 2

• Navy ship parts
• Food processing/pharmaceutical
• Chemical processing equipment
• Anode/cathode/cell parts
• Aircraft ducting, hydraulic, and tubing
• Air pollution control equipment
• Hydrocarbon refining/processing
• Pulp/paper bleaching/washing equipment
• Power plant cooling system components
• Desalination, brine concentration/evaporation
• Hydrometallurgical extraction/electrowinning
• Medical implants/devices, surgical instruments
• Consumer products
• Sports/recreational equipment
• Offshore hydrocarbon production/drilling

Physical Properties

 Titanium Grade 2  Corrosion Resistance

It is also important to note that Grade 2 titanium has a higher corrosion resistance than Grade 5 titanium in certain environments. Grade 2 titanium is highly corrosion-resistant in most natural and industrial environments, while Grade 5 titanium may experience galvanic corrosion in certain conditions.

Heat Treatment

Titanium grade 7 is annealed at 650 – 760°C, still air-cooled. Pickling to remove the alpha case may be needed before further fabrication or machining. Stress relief at 480 – 595°C, air-cooled, may be required to improve dimensional stability for critical components.

Cold Working

The cold work characteristics of this material is similar to that of a moderately tempered austenitic stainless steel. In multiple cold-forming operations, intermediate stress relief is recommended to prevent tearing or other material damage. Post-work annealing is required to reattain optimum performance characteristics

Properties and Applications

While Grade 2 and Grade 5 titanium alloys have unique properties and applications, the biggest difference is their strength. Grade 5 titanium is significantly stronger than Grade 2 titanium and has a higher tensile strength. This means that Grade 5 is better suited for applications that require high strength and durability, such as aerospace engineering.

Strength

In addition to strength, another important factor to consider when choosing between these two titanium alloys is their cost. Grade 5 titanium is typically more expensive than Grade 2 titanium due to its more complex manufacturing process. However, the added cost of Grade 5 titanium is often justified in high-performance applications where strength and durability are paramount.

Titanium Grade 2 Machining

Titanium grade 2 is readily machinable by conventional methods. It is similar to austenitic stainless steels for machinability. Like stainless steel, titanium has a low thermal conductivity and heat dissipation is poor, so generous use of coolant is recommended. Sharp tools are essential. Cuts should be deep and continuous, with low cutting speeds.

Weldability

Titanium grade 2 is readily weldable by GMAW and GTAW processes. Preheat or post-weld heat treatment are not needed. The area immediately surrounding the welds must be CLEAN, free from all grease and shop dirt, including pencil marks. Abrasive cleaning can be used, or solvent cleaning or pickling with a mixture of nitric and hydrofluoric acids. A trailing gas shield must be applied to all areas above 450°C in addition to the normal welding torch gas shield, to prevent heavy oxidation during cooling. Matching filler metal to AWS ERTi-2 is used. The gas shield must be low in hydrogen, oxygen and nitrogen, all of which readily dissolve in titanium and cause embrittlement.

Conclusion

In conclusion, both Grade 2 titanium and Grade 5 titanium are excellent options for various industrial applications. While Grade 2 is the most commercially pure titanium alloy known for its high corrosion resistance, Grade 5 is significantly stronger and better suited for high-performance applications. When deciding between these two alloys, consider your specific use case and weigh the cost versus the added benefits of each. Working with a reputable titanium supplier is always important to ensure you use the right alloy for your application.