ASTM B338 Grade 9 Titanium Tube Titanium Pipes With Forge And Press Or Machanical Processing

ASTM B338 Grade 7 Grade 9 Titanium Tube Titanium Pipes With Forge And Press Or Machanical Processing

Titanium and its alloys have become indispensable materials in various industries, offering a combination of exceptional strength, lightweight properties, and outstanding corrosion resistance. When used in the form of titanium tubes and pipes, they offer unique advantages for a range of industrial applications that require durability and resistance to harsh environments. This article will discuss the key features and uses of pure titanium tubes, titanium pipes, and titanium alloy tubes under ASTM B338 standards, particularly grades Gr5 and Gr7, and explore how they meet the demands of diverse industries.

1. ASTM B338: Overview

ASTM B338 outlines the specification for Titanium Tubes intended for general corrosion-resistant applications and includes titanium and titanium alloy tubes used in various environments, including in chemical processing, marine, and aerospace industries.

The standard applies to seamless and welded tubes, and the tubes are commonly used in applications that require high corrosion resistance, lightweight strength, and durability.

2. Grade 7 Titanium (Ti-0.15Pd)

Grade 7 Titanium is pure titanium (Grade 2) alloyed with palladium (0.12% to 0.25%). Palladium is added to improve the alloy’s corrosion resistance, especially in highly corrosive environments like aeration tanks or chlorine processing applications.

Chemical Composition:

• Titanium (Ti): Balance
• Palladium (Pd): 0.12%–0.25%

Properties:

• Corrosion resistance: Extremely high resistance to corrosion in both oxidizing and reducing acids, including hydrofluoric acid, chlorine, and chlorides.
• Strength: Similar to Grade 2 Titanium but with enhanced corrosion resistance.
• Applications: Marine, chemical, and aerospace applications, as well as heat exchangers and reactors in chemical industries.

Mechanical Properties:

• Tensile strength: 50-70 ksi (345-485 MPa)
• Yield strength: 40-60 ksi (275-415 MPa)
• Elongation: ~20% min

3. Grade 9 Titanium (Ti-3Al-2.5V)

Grade 9 Titanium is an alloy of titanium and two other elements: aluminum (3%) and vanadium (2.5%). This alloy offers improved strength compared to pure titanium (Grade 2) while maintaining excellent corrosion resistance. It’s one of the most popular titanium alloys for use in aerospace, marine, and sports equipment applications.

Chemical Composition:

• Titanium (Ti): Balance
• Aluminum (Al): 3%
• Vanadium (V): 2.5%

Properties:

• Strength: Higher tensile strength and better fatigue resistance than pure titanium (Grade 2).
• Corrosion Resistance: Excellent in seawater and chloride-rich environments.
• Applications: Aerospace, medical devices, sports equipment, and high-performance applications requiring lightweight materials with high strength.

Mechanical Properties:

• Tensile strength: 80-100 ksi (550-690 MPa)
• Yield strength: 70-90 ksi (485-620 MPa)
• Elongation: ~15% min

4. Titanium Tube Manufacturing Process: Forge, Press, and Mechanical Processing

Titanium tubes in ASTM B338 Grade 7 and Grade 9 can be produced through several processes, including forging, pressing, and mechanical processing. Below is a summary of each process and its role in titanium tube fabrication:

Forging

Titanium Forging is the process of shaping titanium billets or ingots by heating and applying pressure. This process is often used to create precise, high-strength parts.

• Process:

  • The titanium alloy is heated to a temperature between 800°C to 1200°C (depending on the grade).
  • The heated billet is then placed in a forging press, where it is shaped into the desired form (such as a tube blank or a solid billet for further machining).
  • The forged titanium is usually made into billets or pre-forms that can later be extruded or pilgered to make seamless pipes and tubes.

• Benefits:

  • Improved material properties (like strength and toughness) due to the refinement of the microstructure.
  • Higher tensile strength and resilience compared to other methods.

Pressing (Mechanical Pressing)

• Mechanical pressing is another method used in the initial forming of titanium tubes. In this process, high pressure is applied to titanium billets to form the shape of a tube or pipe.

• Process:

  • The titanium alloy is heated to a high temperature and placed in a mold.
  • The press applies controlled force to form the tube shape, reducing the diameter and wall thickness of the pipe.

• Benefits:

  • Suitable for mass production of titanium pipes.
  • Helps create thin-walled tubes with uniform dimensions.
  • It can be used for both welded and seamless tubes.

Mechanical Processing (Including Cold Drawing, Pilgering, and Heat Treatment)

After the initial tube formation, mechanical processing like cold drawing and pilgering are used to achieve the precise dimensions required for the final titanium pipe product.

• Cold Drawing: The titanium tube is drawn through a series of dies at room temperature, reducing its diameter and increasing its length. This process also helps to increase the strength and improve the tube's surface finish.

• Pilgering: A process used for reducing the diameter and thickness of a titanium tube. The tube is passed through rotating dies to reduce its size while maintaining uniform thickness.

• Heat Treatment: After mechanical processing, the titanium tube is often subjected to heat treatment (such as annealing) to relieve internal stresses, improve ductility, and enhance its mechanical properties.

• Surface Finishing: The tube may also undergo polishing, passivation, or other surface treatments to improve corrosion resistance and aesthetic appearance.

5. Benefits of Titanium Tubes and Pipes:

Titanium tubes and pipes, especially those made from Gr2, Gr5, and Gr7, offer several key advantages over traditional materials like stainless steel, carbon steel, and other alloys. These benefits include:

Corrosion Resistance:

• Titanium exhibits outstanding resistance to corrosion in most aggressive environments, including seawater, acidic solutions, and chloride-containing compounds. This property makes it ideal for industries like chemical processing, marine, and offshore drilling.

Strength-to-Weight Ratio:

• Titanium has a superior strength-to-weight ratio, making it a lighter alternative to other metals, especially in applications like aerospace and automotive engineering. This results in cost savings due to reduced weight and improved fuel efficiency.

High Temperature Performance:

• Titanium alloys like Gr5 and Gr20 offer excellent performance under high temperatures, providing creep resistance and the ability to perform in heat exchangers, turbine components, and high-pressure applications.

Biocompatibility:

• Pure titanium (Gr2) and certain titanium alloys (Gr7) are biocompatible, making them ideal for medical implants such as orthopedic devices, dental implants, and surgical tools. The body does not reject titanium, allowing for long-term implantation.

Durability and Longevity:

• Titanium is resistant to wear, fatigue, and corrosion, ensuring that titanium pipes and tubes have a long service life, even in extreme environments. This makes titanium a cost-effective solution over time, reducing the need for replacements and repairs.

6. Applications of Titanium Pipes and Tubes:

Titanium pipes and tubes find widespread use across a variety of industries. Here’s a look at how ASTM B338 Gr5 and Gr7 titanium pipes serve key sectors:

Aerospace:

• Titanium’s lightweight and high-strength properties make it perfect for use in aircraft and spacecraft components, including airframes, wings, and engines. Gr5 is widely used for aircraft parts that need to withstand high stresses and temperatures.

Chemical Processing:

• The corrosion resistance of titanium is highly beneficial in chemical plants that process aggressive substances like sulfuric acid, chlorides, and hydrochloric acid. Gr7 titanium pipes are used in heat exchangers, reactors, and piping systems that require high resistance to aggressive chemicals.

Marine Industry:

• Marine environments are highly corrosive, with seawater and salt exposure putting immense stress on materials. Titanium tubes and pipes, particularly Gr2, offer corrosion resistance in saltwater and are used in shipbuilding, submarine components, and offshore oil platforms.

Medical:

• Titanium’s biocompatibility makes it an ideal choice for medical implants such as hip replacements, knee implants, and dental implants. Its lightweight and strong nature make it comfortable and functional in the human body.

Oil and Gas Industry:

• Titanium’s ability to resist high-pressure and high-temperature environments makes it crucial for offshore drilling and petroleum extraction applications. Gr5 and Gr7 titanium pipes are used in subsea pipelines, wellheads, and heat exchangers.

7. Chemical Composition of ASME SB338 Ti Gr 2 Seamless Pipe

8. Summary of Titanium Pipe Manufacturing Process

1. Raw material preparation: Titanium sponge is processed into billets or ingots.
2. Extrusion or piercing: The billet is extruded or pierced to form a hollow tube.
3. Pilgering (Cold Drawing): The pipe is reduced in size and thickness through cold drawing.
4. Heat treatment: The pipe undergoes annealing or solution annealing to enhance properties.
5. Sizing and straightening: The pipe is resized and straightened to meet specifications.
6. Finishing: Polishing, beveling, and surface treatments improve surface quality.
7. Quality control and testing: Pipes undergo rigorous testing to ensure they meet standards.
8. Packaging and shipping: The pipes are prepared for delivery to customers.

The manufacturing of titanium pipes involves a combination of precision machining, heat treatment, and surface finishing techniques that ensure the pipes meet the high standards required for critical applications. This process results in titanium pipes that offer outstanding strength, lightweight properties, and corrosion resistance, making them essential components for industries like aerospace, chemical processing, and marine engineering.

9. Titanium Tube Sizes: