Super Duplex 32750

Ferrite-Austenitic stainless steel

32750 is characterized by:

  • Excellent corrosion resistance against general corrosion, stress corrosion cracking, corrosion fatigue, pitting, crevice and erosion corrosion
  • Possessing very high mechanical strength properties
  • Good weldability, post weld heat treatment not necessary
  • Max temperature for long periods of service 280°C (536°F)

Super Duplex 32750 Stainless Steel

Additional Information About Super Duplex 32750

Stainless steel was originally developed to combat steel corrosion. Over the decades, these developers have proved to be more than up to the task. One of the results is Super Duplex 32750.

Duplex grade stainless steel alloys have properties that are half austenitic and half ferritic. One of the biggest problems with stainless steel has always been rusting, and when these two properties were put together, the oxidation problem came to an end. This grade of stainless steels was developed more than 70 years ago in Sweden for use in the sulfite paper industry. Duplex stainless steel was originally created to combat the high corrosion problems that were brought on by chemical process fluids.

By combining austenite and ferrite, the stainless steel duplex grade has been given superior strength and excellent resistance to oxidation. Duplex stainless steel is about twice as strong as regular ferritic or austenitic metals. Due to its increased yield strength, duplex stainless steels can be created in thinner sections. This means the weight of the stainless steel has been significantly decreased. Duplex stainless steel has become, over time, a popular choice for pressure vessels, and structural applications.

The duplex grade family of stainless steel applications has a wide variety of specific formulations. S31803 (2205) and super duplex S32750 (2507) are the most common of these formulations. Both of these products are extremely versatile in the world of stainless steel. They are used in many and diverse applications throughout the world. You will find both duplex and super duplex stainless steel used in the petrochemical, oil, gas, and chemical processing industries.

The term “Super Duplex” was coined in the 1980s and it denoted highly alloyed, high-performance Duplex steel. Because there is such a high level of Chromium in Super Duplex stainless steel, it can withstand resistance to acids, acid chlorides, caustic solutions, and other environments found in the industries where it is used.

Super Duplex Stainless Steel 32750

Super Duplex stainless steel 32750 has all of the characteristics of Duplex stainless steel. The only difference between Duplex and Super Duplex is that Super Duplex has a higher Chromium and Molybdenum content, which makes it even better at combating corrosion resistance.

Corrosion that occurs in duplex and super duplex stainless steels are:

  • Pitting corrosion. The passive layer of stainless steel can be attacked by particular chemicals in nature. The chloride ion Cl is the most common of these and is found in things such as bleach and salt.
  • Crevice corrosion. Stainless steel requires a degree of oxygen to ensure that the passive layer can form on the surface. In very tight spaces, the oxygen may have trouble gaining access to the surface, which makes it vulnerable to attack.
  • General corrosion. Under normal conditions, stainless steel does not corrode uniformly. Due to temperature or concentration, the passive layer may be attacked uniformly, especially through acids. The metal loss is distributed over the entire surface of the stainless steel.
  • Stress corrosion cracking. This type of corrosion is rare and only brought about due to the combination of temperature, tensile stress, and corrosive species, usually the chloride ion.
  • Galvanic corrosion. When two dissimilar metals come together, corrosion can be accelerated in the lesser of the two metals.
  • Intergranular corrosion. This is a very rare corrosion and can occur during welding.

Super duplex stainless steel is needed in applications where high strength and the ability to combat highly corrosive conditions is warranted. Stainless steel Super Duplex S32750 is designed to handle such situations. Super Duplex 32750 has a high content of Molybdenum, Chromium, and Nitrogen, making it perfect for withstanding high corrosion and pitting.

In addition, Super Duplex S32750 is also highly resistant to chloride stress corrosion cracking, corrosion fatigue, erosion corrosion, and to general corrosion in acids. 32750 has a high mechanical strength and very good weldability.

The chemical composition of stainless steel Super Duplex S32750 is made up of:

  • Chromium
  • Nickel
  • Molybdenum
  • Manganese
  • Silicon
  • Copper
  • Nitrogen
  • Phosphorous
  • Carbon
  • Sulfur
  • Iron

Throughout the years, Duplex stainless steel and now Super Duplex stainless steel have enjoyed a steady increase in popularity. Super Duplex S32750 is used in the following industries:

  • Petrochemical
  • Chemical
  • Power
  • Oil and gas production
  • Marine
  • Water desalinization
  • Pulp and paper

Products made from Super Duplex S32750:

  • Hydraulic piping
  • Cargo tanks
  • Wire
  • Fittings
  • Fans
  • Storage vessels
  • Water heaters
  • Heat exchangers
  • Spiral wound gaskets
  • Hot water tanks
  • Lifting and pulley equipment
  • Propellers, rotors, and shafts

For a stainless steel with enhanced corrosion resistance and good weldability, Super Duplex 32750 is unlikely to disappoint. Contact our experienced team at Metals 28 at 708-375-5617.