Applications of Duplex Steel

Duplex steels are the latest group of tempered steels. Duplex stainless steels are designated “duplex” (or austenitic-ferritic) since they have a two-stage micro-structure comprising of grains of ferritic and austenitic treated steel. They are utilized for their great mechanical properties.

Duplex Steel are normally partitioned in three gatherings:

1. Standard Duplex, commonly Grade EN 1.4462. It was the first one to be developed and represents the “mid-range” of properties and is the most utilized duplex steel today. Ex: https://www.numaxsteels.com/duplex-steel-uns-s32205-sheets-plates-coils.php

2. Super-duplex typically grades EN 1.4410 up to supposed Hyper duplex evaluations grew later to satisfy the explicit needs of the oil & gas just as those of the chemical industries. They offer a prevalent corrosion opposition and strength however are progressively hard to process on the grounds that they have higher contents of Cr, Ni, Mo, N, and even W promote the formation of intermetallic stages, which diminish radically the impact obstruction of the steel. Defective preparing will bring about poor performance and users are encouraged to deal with trustworthy suppliers/processors. Applications incorporate deepwater seaward oil creation.

3. Lean Duplex grades, normally level EN 1.4362, have been grown recently for less requesting applications, especially in the building and construction industry. Their corrosion opposition is nearer to that of the standard austenitic evaluation EN 1.4401 and their mechanical properties are higher. This can be an incredible preferred advantage when strength is important. This is the situation in bridges, pressure vessels or tie bars.

Duplex Stainless Steel has quite a lot of applications in these industry categories:

  • Chemical Process
  • Petrochemical
  • Oil & Gas
  • Pharmaceutical
  • Geothermal
  • Sea Water
  • Water Desalination
  • LNG (Liquefied Natural Gas)
  • Biomass
  • Mining
  • Utilities
  • Nuclear Power
  • Solar Power

Duplex Stainless Steel is suitable for many industrial processes. A few environments in which it is fully resistant are:-

  • Ammonium Bicarbonate
  • Ammonium Bromide
  • Ammonium Carbonate
  • Ammonium Hydroxide
  • Ammonium Oxalate
  • Ammonium Phosphate
  • Ammonium Sulfate
  • Ammonium Sulfide
  • Ammonium Sulfite
  • Benzoic Acid
  • Calcium Chloride
  • Calcium Hydroxide
  • Calcium Nitrate
  • Carbon Tetrachloride
  • Chlorobenzene
  • Copper Acetate
  • Copper Carbonate
  • Copper Cyanide
  • Cupric Chloride
  • Ethyl Chloride
  • Gallic Acid
  • Magnesium Carbonate
  • Magnesium Chloride
  • Magnesium Sulfate
  • Malic Acid
  • Mercuric Cyanide
  • Mercuric Nitrate
  • Nitric Acid
  • Nitrous Acid
  • Perchloric Acid
  • Phosphoric Acid
  • Picric Acid
  • Potassium Bromide
  • Potassium Cyanide
  • Potassium Dichromate
  • Potassium Hydroxide
  • Potassium Iodide
  • Potassium Oxalate
  • Potassium Permanganate
  • Potassium Sulfate
  • Pyrogallic Acid
  • Quinine Bisulfate (Dry)
  • Quinine Sulfate (Dry)
  • Silver Bromide
  • Silver Nitrate
  • Sodium Acetate
  • Sodium Bicarbonate
  • Sodium Bisulfate
  • Sodium Bromide
  • Sodium Chlorate
  • Sodium Chlorite
  • Sodium Nitrate
  • Sodium Nitrite
  • Sodium Peroxide
  • Sodium Silicate
  • Sodium Sulfate
  • Sodium Sulfide
  • Sodium Sulfite
  • Stannic Chloride
  • Sulfuric Acid
  • Sulfurous Acid
  • Urea
  • Zinc Chloride
  • Zinc Sulfate

Applications of Duplex Stainless Steel

The name “Duplex” is termed because there are 2 phases of ferrite and austenite grains in the microstructure. When melted, duplex stainless steel solidifies. It gets converted to the ferric structure. At room temperature, the ferritic grains convert to austenitic grains. The resulting structure is a 50-50 combination of ferrite and austenite. When compared to other austenitic alloys, Duplex stainless steel has great strength and good resistance against stress corrosive cracking. When compared to ferritic alloys, the duplex has greater toughness.

Following are the few applications of Duplex stainless steel used as

  • Spargers
  • Pipe
  • Piping systems
  • Reactors
  • Pressure Vessels
  • Condensers
  • Heater Exchangers
  • Columns

Also, the applications of duplex stainless steel are found in the following industries namely

  • Chemical Process
  • Petro Chemical
  • Pharmaceutical
  • Oil and Gas
  • Seawater
  • Geothermal
  • LNG
  • Water desalination
  • Mining
  • Biomass
  • Utilities
  • Solar and nuclear power

Different industrial processes use duplex stainless steel and it is used in various environments like

  • Ammonium Bromide
  • Ammonium Bicarbonate
  • Ammonium Carbonate
  • Ammonium Oxalate
  • Ammonium Phosphate
  • Ammonium Hydroxide
  • Ammonium Sulfate
  • Ammonium Sulfide
  • Ammonium Sulfite
  • Benzoic Acid
  • Calcium Hydroxide
  • Calcium Chloride
  • Calcium Nitrate
  • Carbon Tetrachloride
  • Chlorobenzene
  • Cupric Chloride
  • Copper Cyanide
  • Copper Acetate
  • Copper Carbonate
  • Ethyl Chloride
  • Gallic Acid
  • Magnesium  Carbonate
  • Magnesium Chloride
  • Magnesium Sulfate
  • Malic Acid
  • Nitrate
  • Cyanide
  • Nitric Acid
  • Phosphoric Acid
  • Perchloric Acid
  • Picric Acid
  • Nitrous Acid
  • Potassium Iodide
  • Potassium Dichromate
  • Potassium Bromide
  • Potassium Hydroxide
  • Potassium Oxalate
  • Potassium Cyanide
  • Potassium Permanganate
  • Potassium Sulfate
  • Quinine Sulfate (Dry)
  • Pyrogallic Acid
  • Quinine Bisulfate (Dry)
  • Silver Bromide
  • Silver Nitrata
  • Sodium Sulfide
  • Sodium Acetate
  • Sodium Peroxide
  • Sodium Bromide
  • Sodium Bisulfate
  • Sodium Chlorate
  • Sodium Nitrate
  • Sodium Chlorite
  • Sodium Nitrite
  • Sodium Sulfite
  • Sodium Sulfate
  • Sodium Bicarbonate
  • Sodium Silicate
  • Stannic Chloride
  • Sulfuric Acid
  • Sulfurous Acid
  • Urea
  • Zinc Sulfate
  • Zinc Chloride

Cost advantages of Duplex stainless steel

While comparing with austenitic stainless steel, the duplex offers more thermal conductivity because of the low amount of nickel content. Hence, there is added advantage of using duplex stainless steel for heat exchangers. The same duty can be performed with a lesser heat transfer rate. If passing ASME code is the only criterion, then welding becomes easy with duplex stainless steel.

However, it is necessary to consider the welding mixture and right handling is required to succeed in corrosion resistance. Duplex is a better option and best material consideration for a project.  Consulting a familiar and popular stainless steel duplex welder is advisable. A good duplex stainless steel welder can help to engineer, build and inspect high standards.