Chemical Composition and Mechanical Properties of SUS347 Stainless Steel

SUS347 is a niobium (columbium)-stabilized austenitic stainless steel with the following composition and properties:

Chemical Composition:

Mechanical Properties:

Applications and Industries Using SUS347 Stainless Steel

SUS347 is ideal for high-temperature and corrosive environments due to its excellent mechanical properties and resistance to intergranular corrosion:

1. Aerospace Industry: Used in engine parts, gas turbines, and exhaust systems.
2. Petrochemical Industry: Employed in cracking units, refining devices, and heat exchangers.
3. Power Generation: Suitable for high-pressure steam environments such as boilers and nuclear power plants.
4. Food Processing Equipment: Applied in cookers, drying equipment, and other high-temperature food processing machinery.
5. Chemical Processing: Used in reactors, storage tanks, and piping systems.
6. Marine Applications: Ideal for components exposed to saltwater environments.

Manufacturing Process of SUS347 Stainless Steel

The manufacturing process involves several steps:

1. Melting Raw Materials: Raw materials like iron ore, chromium, nickel, and niobium are melted in an electric arc furnace.
2. Refining: The molten metal is refined using Argon Oxygen Decarburization (AOD) or Vacuum Oxygen Decarburization (VOD).
3. Casting: The refined molten steel is cast into slabs or billets.
4. Hot Rolling: The slabs are hot-rolled into sheets or plates.
5. Cold Rolling: Further rolling at room temperature achieves the final dimensions.
6. Heat Treatment: Solution annealing at 1050-1150°C followed by rapid cooling ensures optimal mechanical properties.

Comparison of SUS347 with Other Stainless Steel Grades

SUS347 offers superior resistance to intergranular corrosion compared to SUS304 and better high-temperature strength than both SUS304 and SUS321.

Corrosion Resistance and Heat Treatment of SUS347

Corrosion Resistance:

• Resistant to intergranular corrosion due to niobium stabilization.
• Performs well in environments containing acids, alkalis, and salts.
• Suitable for applications with temperatures ranging from 800°F to 1500°F (427°C to 815°C).

Heat Treatment:

• Solution annealing: Heat to 1050-1150°C followed by rapid cooling.
• Does not require post-weld annealing due to its stabilized structure.

Advantages of Using SUS347 in High-Temperature Applications

1. Excellent resistance to oxidation up to 1500°F (815°C).
2. High creep strength in elevated temperature environments.
3. Superior resistance to carbide precipitation during welding or prolonged heat exposure.

At HL Steel Company, we supply high-quality SUS347 stainless steel products for various industries, ensuring durability, corrosion resistance, and performance in demanding applications such as aerospace, petrochemical processing, and power generation systems.