Cast Stainless Steel CF8

Cast stainless steel CF8 is a common designation for a type of austenitic stainless steel. Austenitic stainless steels are a class of alloys known for their excellent corrosion resistance, high-temperature strength, and good formability. They are widely used in various industries, including automotive, aerospace, food processing, and chemical processing, due to their versatility and durability

The characteristics of CF8

  • Corrosion Resistance:

    CF8 stainless steel offers excellent corrosion resistance, particularly in environments where exposure to moisture, acids, and salts is common.

    It is highly resistant to rust and staining, making it suitable for applications in wet or corrosive environments.

  • Heat Resistance:

    CF8 can withstand moderately high temperatures, making it suitable for use in applications involving exposure to elevated temperatures, such as industrial furnaces or exhaust systems.

  • Formability and Weldability:

    CF8 is known for its good formability, which allows it to be easily fabricated into various shapes through processes like machining, welding, and forming.

    Weldability is generally good, but care must be taken to use the appropriate welding techniques and filler materials to avoid issues like sensitization, which can reduce corrosion resistance.

Typical Applications of cast stainless steel CF8

Cast stainless steel CF8, also known as AISI 304 or 18-8 stainless steel, is a commonly used material in various industrial applications due to its corrosion resistance, durability, and ease of fabrication. Here are some typical applications for CF8 stainless steel:

  1. Food Processing Equipment: CF8 stainless steel is widely used in the food and beverage industry for equipment like tanks, piping, and food handling machinery due to its corrosion resistance and ability to maintain product purity.
  2. Chemical Processing: It is used in the chemical industry for pumps, valves, and fittings where resistance to corrosive chemicals is essential.
  3. Pharmaceutical Equipment: CF8 stainless steel is suitable for pharmaceutical manufacturing equipment such as mixers, reactors, and storage tanks where hygiene and corrosion resistance are critical.
  4. Marine Equipment: It is used in marine applications for components like propellers, boat fittings, and marine hardware due to its resistance to saltwater corrosion.
  5. Petrochemical Industry: CF8 is utilized in the construction of valves, pumps, and other equipment in the petrochemical industry where exposure to harsh chemicals and extreme temperatures is common.
  6. Agricultural Equipment: It can be found in agricultural machinery parts and equipment that require resistance to corrosion, such as irrigation systems, tanks, and processing equipment.
  7. Automotive: Some automotive components, particularly in exhaust systems and parts exposed to road salt, may use CF8 stainless steel to prevent corrosion.
  8. HVAC Systems: CF8 is suitable for HVAC (Heating, Ventilation, and Air Conditioning) applications, including ductwork, heat exchangers, and components that need to withstand various environmental conditions.
  9. Architectural and Construction: It is used in architectural applications like railings, facades, and decorative elements because of its aesthetic appeal, corrosion resistance, and low maintenance.
  10. Nuclear Power: Some components of nuclear power plants, particularly those exposed to high-temperature water or steam, use CF8 stainless steel due to its resistance to corrosion and radiation.
  11. Oil and Gas: CF8 can be found in various components of oil and gas exploration and production equipment, including valves, pumps, and pipelines.
  12. Water Treatment: In water treatment plants, CF8 stainless steel is used for piping, tanks, and equipment that come into contact with water and various chemicals.
  13. Aerospace: In some aerospace applications, CF8 stainless steel is used for parts requiring corrosion resistance, such as aircraft fuel systems.
  14. General Manufacturing: CF8 stainless steel can be used in various manufacturing processes and equipment, including conveyors, hoppers, and material handling systems.
  15. Renewable Energy: It is used in components of renewable energy systems, such as wind turbines and solar panel mounting structures, due to its resistance to environmental factors.                                                                                                                                                                                                                                                                                   It’s important to note that CF8 stainless steel is just one of many stainless steel alloys available, each with its own specific properties and applications. The choice of stainless steel grade depends on the specific requirements of the application, including factors like temperature, chemical exposure, and mechanical stress.

Stainless Steel CF8 material equivalent

  • ASTM A351 Grade CF8: This is the ASTM (American Society for Testing and Materials) designation for cast austenitic stainless steel. CF8 corresponds to AISI 304 stainless steel.

  • DIN 1.4308: This is the German DIN standard designation for a similar material. It is also equivalent to AISI 304 stainless steel.

  • JIS SUS304: In the Japanese Industrial Standards (JIS) system, CF8 is similar to JIS SUS304, which is again equivalent to AISI 304 stainless steel.

CF8 chemical composition

Carbon (C): ≤ 0.08%

Silicon (Si): ≤ 2.00%

Manganese (Mn): ≤ 1.5%

Phosphorus (P): ≤ 0.04%

Sulfur (S): ≤ 0.04%

Chromium (Cr): 18.00% – 21.00%

Nickel (Ni): 8.00% – 11%

Molybdenum: 0.50% Max

Physical Properties

  • Yield Strength:
    30 ksi Min
  • Tensile Strength:
    70 ksi Min
  • Elongation at 2 in:
    35% Min
    Stainless Steel CF8 pipe
    Stainless Steel CF8 pipe

CF8 Casting Heat treatment process

Heat the casting to a temperature between 1900°F (1040°C) and 2050°F (1120°C).
Hold the casting at this temperature for a sufficient amount of time to allow the alloying elements to diffuse evenly.
The recommended soaking time is typically 30 minutes per inch of thickness (about 25mm) for the casting.
After soaking, quench the casting rapidly in water or a suitable quenching medium to cool it down to room temperature. This step helps to dissolve any carbides and create a homogeneous microstructure.

It’s important to note that the exact heat treatment parameters (temperatures, times, and cooling rates) may vary depending on the specific grade of CF8 stainless steel, the size and geometry of the casting, and the desired mechanical properties. Therefore, it is advisable to consult the material supplier or a metallurgical expert for precise heat treatment recommendations for your particular CF8 casting.