Super alloy Elgiloy is a cobalt-chromium-nickel alloy, and provides high strength, fatigue life, ductility, and good mechanical properties. It is also corrosion resistant in various environments. It is recommended that forming should be done before heat treatment as heat treatment strengthens the material and makes it more difficult to form.
Elgiloy is a non-magnetic Cobalt-Chromium-Nickel-Molybdenum alloy having a unique combination of very high strength while maintaining excellent formability, excellent corrosion resistance, and high fatigue strength. Additional strength increases of up to 25% can be achieved through aging cold-reduced material. Elgiloy is highly resistant to sulfide stress corrosion cracking and, as a result, is the alloy of choice in the most demanding sour well environments. In seawater, Elgiloy is virtually immune to crevice and stress corrosion and pitting, even at the highest strength levels. Elgiloy performs across a wide range of temperatures, from cryogenic up to 850°F (454°C).
1. What is Elgiloy Alloy?
1.1. Historical Background
Elgiloy is a registered trademark of Elgiloy Specialty Metals, a company renowned for its production of high-performance alloys. This alloy was developed in the late 1960s as a response to the growing demand for materials with exceptional mechanical and corrosion-resistant properties. Elgiloy alloy is known for its unique combination of elements and precise manufacturing processes that yield a material well-suited to diverse and challenging applications.
Elgiloy alloy is primarily composed of cobalt, chromium, nickel, molybdenum, and iron. The following is the typical composition of superalloy elgiloy:
- Cobalt (Co): Approximately 40–45%
- Chromium (Cr): Approximately 20–23
- Nickel (Ni): Approximately 14–16%
- Molybdenum (Mo): Approximately 4.0–6.0%
- Iron (Fe): Balancing element
This composition, when combined with a controlled manufacturing process, gives Elgiloy alloy its distinctive properties.
1.3. Manufacturing Process
Super alloy Elgiloy is produced using a series of carefully controlled and documented steps. The manufacturing process involves vacuum induction melting (VIM) and vacuum arc remelting (VAR), ensuring a high level of purity and homogeneity in the material. After remelting, the alloy is hot-rolled, cold-worked, and heat-treated to achieve the desired mechanical and metallurgical properties.
Elgiloy’s unique manufacturing process ensures that the alloy exhibits exceptional mechanical and chemical properties, making it suitable for various applications.
2. Mechanical Properties of Elgiloy Alloy
Super alloy Elgiloy‘s mechanical properties are a testament to its strength and durability, making it a material of choice for demanding applications.
2.1. Tensile Strength
Elgiloy alloy boasts an impressive tensile strength, typically ranging from 155,000 to 200,000 pounds per square inch (psi). This high tensile strength allows it to withstand heavy loads and extreme conditions, making it ideal for applications where structural integrity is paramount.
2.2. Yield Strength
The yield strength of Super alloy Elgiloy typically falls within the range of 145,000 to 190,000 psi. This property signifies the point at which the material undergoes plastic deformation, making it important for applications where elastic recovery is crucial.
2.3. Modulus of Elasticity
The modulus of elasticity of Elgiloy alloy is approximately 30 million psi. This property indicates the material’s ability to return to its original shape after deformation, a critical feature for applications involving repeated stress cycles.
Super alloy Elgiloy exhibits a high level of hardness, with a typical Rockwell C hardness ranging from 35 to 40 HRC. This hardness contributes to its resistance to wear and deformation, enhancing its longevity in service.
2.5. Fatigue Resistance
Elgiloy alloy’s fatigue resistance is particularly noteworthy. It can withstand a high number of stress cycles without experiencing fatigue failure, which is essential for applications with repetitive loads.
These remarkable mechanical properties make superalloy elgiloy suitable for applications where strength, resilience, and longevity are of utmost importance.
3. Chemical and Corrosion Resistance
Elgiloy alloy’s chemical composition and manufacturing process contribute to its exceptional corrosion resistance.
3.1. Chemical Composition
The combination of cobalt, chromium, nickel, and molybdenum imparts outstanding resistance to corrosion from various chemical environments, including:
- Sulfuric acid
- Hydrochloric acid
- Nitric acid
This resistance to chemical corrosion is a key factor that has propelled Superalloy Elgiloy into industries where exposure to corrosive agents is a constant challenge.
3.2. Corrosion Resistance
Elgiloy alloy’s resistance to corrosion is not limited to chemical environments. It also exhibits impressive resistance to:
- Pitting corrosion
- Crevice corrosion
- Stress corrosion cracking
This corrosion resistance ensures the long-term reliability of components made from Elgiloy alloy, even in harsh conditions.
3.3. Compatibility with Various Environments
Elgiloy alloy is compatible with a wide range of environments, making it an ideal choice for applications in:
- Medical and healthcare settings
- Aerospace and aviation industries
- Oil and gas exploration and production
- Chemical processing
- Marine environments
The ability to thrive in such diverse conditions highlights the versatility and adaptability of the Elgiloy alloy.
Elgiloy is a non-magnetic Cobalt-Chromium-Nickel-Molybdenum alloy having a unique combination of very high strength while maintaining excellent formability, excellent corrosion resistance, and high fatigue strength. Additional strength increases of up to 25% can be achieved through aging cold reduced material. Elgiloy is highly resistant to sulfide stress corrosion cracking, and as a result is the alloy of choice in the most demanding sour well environments. In seawater, Elgiloy is virtually immune to crevice and stress corrosion and pitting even at the highest strength levels. Elgiloy performs across a wide range of temperatures: from cryogenic up to 850°F (454°C).
3J21 high elastic alloy has non-magnetic, corrosion resistance, high elasticity, high strength and good fatigue resistance
|Density||8.30 g/cm3||0.300 lb/in3|
|Tensile strength||970 MPa||141000 psi|
|Yield strength||480 MPA||69600 psi|
|Elastic modulus||189.6 GPa||27500 ksi|
|Hardness, Rockwell A||60||60|
|Hardness, Rockwell B||97||97|
|Hardness, Rockwell C||19||19|
|Thermal expansion co-efficient (at 0.000-500°C/32-932°F)||15.17 µm/m°C||8.42 µin/in°F|
|Thermal conductivity||12.5 W/mK||86.8 BTU in/hr.ft².°F|
- Bars & Rods & Foring Ring /Flanges
- Sheet & Plate
- Strip & Coil
- Welding Wire &Spring wire
- Seamless Tube & Welded Pipe
»Round Bar & Square Bar & Hexagon Bar
● Diameter : φ8～φ300mm Length:10mm-6000mm
● Hot forging, Hot Rolling, Cold Drawing
● Bright Surface, Polished Surface, Black Surface
»Tube & Pipe:Seamless Tube& Welded Pipe
● Cold Drawing Seamless Pipe： φ1.0～φ220mm
● Hot Extrusion pipe: φ50～φ250mm
● Others : U Blend Tube and Elbow
»Hot Rolled Plate & Cold Rolled Sheet
● Cold Rolling Sheet Thickness: ≦2.0mm Width:≦1500m
● Hot rolling Plate Thickness: ≧4.0mm Width: ≦2500m
»Strip & Tape Ribbon
● Thickness: ≧ 0.01mm Width: 15mm-300mm
● Cold rolling BA Strip, Hard & Soft Condition
»Straight Length Wire & Spool Wire
● Welding Wire: φ 0.1mm～6.0mm Cut length Rod: φ1.0～φ8.0mm
● Package : 5-25kg/Spool or Box
Super alloys are widely used in numerous industries to make components such as gas turbine engines, rocket motors, nuclear reactors, submarines, and petroleum equipment.
4. Applications of Elgiloy Alloy
Super alloy Elgiloy‘s exceptional properties have led to its adoption in several critical applications across different industries. Let’s explore some of the key sectors where Super alloy Elgiloy shines:
4.1. Medical and Dental Devices
Elgiloy alloy is widely used in the medical and dental fields due to its biocompatibility, corrosion resistance, and high fatigue strength. It can be found in applications such as:
- Springs in surgical instruments
- Dental and orthodontic wires
- Pacemaker leads
- Orthopedic implants
- Endodontic files
Its compatibility with the human body, combined with its mechanical and corrosion-resistant properties, makes Elgiloy alloy a trusted material for life-saving medical devices.
4.2. Aerospace Industry
In the aerospace industry, superalloy Elgiloy’s combination of strength, fatigue resistance, and corrosion resistance is highly valued. It is employed in:
- Aircraft engine components
- Precision springs
- Seals and gaskets
- Fuel system components
These critical aircraft components rely on the durability and reliability of superalloy Elgiloy to ensure safe and efficient flight operations.
4.3. Oil and Gas Exploration
The oil and gas industry demands materials that can withstand the harsh and corrosive conditions found in drilling, extraction, and processing. Elgiloy alloy is used in:
- Downhole tools
- Safety valve components
- Subsea connectors
- Drill collars
- Gas lift mandrels
Its corrosion resistance and high tensile strength enable the superalloy Elgiloy to endure extreme pressure, temperature, and corrosive environments.
In the electronics industry, elgiloy alloy finds applications due to its electrical conductivity and resistance to corrosion. It is utilized in:
- Electrical connectors
- Fuse clips
- Relay springs
- Precision instruments
- Electrical contacts
These components rely on the reliability and longevity that Elgiloy alloy provides, ensuring uninterrupted electronic functionality.
4.5. Automotive Industry
The automotive sector values materials that offer high strength and resilience. Elgiloy alloy is used in applications such as:
- Valve springs
- Fuel injection systems
- Airbag initiators
- Timing chains
Its mechanical properties contribute to the efficiency and durability of automotive components.
5. Benefits of Elgiloy Alloy
Super alloy Elgiloy’s advantages extend beyond its remarkable properties and versatility. Let’s delve into the key benefits that make it a preferred material:
Elgiloy alloy is biocompatible, meaning it is well-tolerated by the human body and does not trigger adverse reactions or sensitivities. This property is vital for medical and dental applications, where materials come into direct contact with human tissues and fluids.
5.2. High Strength-to-Weight Ratio
Super alloy Elgiloy offers a high strength-to-weight ratio, allowing it to provide exceptional strength and performance while keeping weight to a minimum. This makes it particularly valuable in applications where lightweight materials are essential for efficiency and performance.
5.3. Resistance to Extreme Temperatures
Elgiloy alloy remains stable and maintains its properties across a wide temperature range. It can withstand both extreme cold and high-temperature environments, making it suitable for applications in aerospace, oil and gas, and other industries where temperature extremes are common.
5.4. Long-Term Durability
The combination of corrosion resistance and fatigue resistance ensures that components made from superalloy Elgiloy have an extended service life. This results in reduced maintenance and replacement costs for equipment and devices.
5.5. Ease of Machinability
Elgiloy alloy is known for its machinability. It can be easily formed, cut, and shaped, allowing for the efficient production of complex components with precision.
These benefits collectively make superalloy elgiloy an attractive choice for engineers, manufacturers, and designers seeking materials that deliver reliability, longevity, and performance in their applications.
6. Considerations When Using Super alloy Elgiloy
While elgiloy alloy offers numerous advantages, there are several important considerations to keep in mind when working with this material.
6.1. Welding and Joining
Welding and joining Super alloy Elgiloy can be challenging due to its unique composition and the need to maintain its properties. Proper welding procedures and expertise are essential to prevent brittleness and maintain corrosion resistance.
6.2. Heat Treatment
Super alloy Elgiloy requires careful heat treatment to optimize its mechanical properties. The right heat treatment processes are crucial to achieving the desired strength, hardness, and ductility.
6.3. Surface Finishing
Surface finishes and coatings can be applied to Elgiloy alloy to enhance its corrosion resistance and appearance. These treatments should be chosen carefully based on the intended application.
6.4. Regulatory Compliance
In certain applications, especially in the medical and aerospace industries, regulatory compliance is critical. Ensure that the use of Super alloy Elgiloy meets industry-specific standards and certifications.
Elgiloy alloy is a remarkable material with a rich history, unique properties, and a broad spectrum of applications. Its exceptional combination of strength, corrosion resistance, and biocompatibility makes it a preferred choice in industries where reliability and longevity are paramount.
Whether in life-saving medical devices, cutting-edge aerospace technology, or the demanding environments of the oil and gas sector, superalloy Elgiloy continues to demonstrate its versatility and adaptability. As ongoing research and innovation drive the material’s development, it is likely to remain a key player in shaping the future of various industries. By understanding the properties, advantages, and considerations associated with Elgiloy alloy, engineers, manufacturers, and designers can harness its potential to create products and systems that meet the highest standards of performance, safety, and longevity.