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.