Calico Metal Alloys LLP is a reputable supplier and exporter of Duplex Steel UNS S31803 Pipes in India. Among our top offerings are Duplex Steel UNS S31803 Pipes, known for their exceptional strength, corrosion resistance, and versatility. We pride ourselves on delivering high-quality products that meet stringent industry standards, making us a trusted partner for various applications in sectors such as construction, oil and gas, and manufacturing. With a commitment to reliability and customer satisfaction, we stand out as a premier source for premium-grade duplex steel pipes in the Indian market.

What is Duplex Steel UNS S31803 Pipes?

Duplex Steel UNS S31803 Pipes are a type of stainless steel pipes known for their excellent corrosion resistance and high strength. They are composed of a balanced microstructure of austenite and ferrite phases, offering superior toughness and durability. These pipes are widely used in various industries such as chemical processing, oil and gas, and marine applications due to their exceptional performance in harsh environments.

Duplex Steel UNS S31803 Pipes

Manufacturing Process Of Duplex S31803 Pipes

Rolling and Welding

The strips pass through the number of rollers as per the required size. In the tubes-mill, the strip is gradually converted into the tubular shape. The fitted welding machine is then used to weld trim edges of the strip using TIG welding process.

Length Cutting

Rolled pipes and tubes thus manufactured are cut to the required lengths depending upon the industrial demand. We use a variety of methods—sawing, lathe cutting, rotary cutting, supported shear cutting, dual-blade shear cutting, and laser cutting.

Cleaning and Heating Phase

Subjected to cleaning to remove the dirt. Further, a heat treatment is given to these rolled pipes and tubes to remove the stresses that may occur due to welding and formation processes. Heat treatment is given on the continuously rolling hearth furnace.

Cold Drawing Process

Required size may not be obtained from the mill directly. Then, the cold operation process can be used to obtain the desired size. In the cold drawing process, the tube or pipe is drawn over the bench using Die plugs.

Finishing Process

Pipe and tubes are then subjected to cleaning, heat treatment, pickling and straightening. The computerized ink jet marking machine then mark the finished pipes or tubes. Then they marked with grade of material, size, heat number.

Advantages of Duplex Steel UNS S31803 Pipes

Duplex Steel UNS S31803 pipes offer numerous advantages due to their unique composition and properties. Here are some of the key advantages:

Corrosion Resistance: One of the most significant advantages of Duplex Steel UNS S31803 pipes is their excellent resistance to corrosion, particularly in harsh environments such as those containing chloride ions. This makes them suitable for use in offshore and marine applications, as well as in chemical processing industries.

High Strength: Duplex Steel UNS S31803 pipes have higher strength compared to austenitic or ferritic stainless steels, allowing for the design of lighter and more compact piping systems without sacrificing structural integrity.

Good Toughness and Ductility: These pipes exhibit good toughness and ductility even at low temperatures, making them suitable for use in cryogenic applications.

High Resistance to Stress Corrosion Cracking (SCC): Duplex steels, including UNS S31803, have superior resistance to stress corrosion cracking, which is a common issue in many corrosive environments.

Cost-Effective: While duplex stainless steels may have a higher initial cost compared to austenitic stainless steels, their longer service life and reduced maintenance requirements often result in cost savings over the lifespan of the piping system.

Versatility: Duplex Steel UNS S31803 pipes are versatile and can be used in a wide range of applications, including oil and gas exploration and production, chemical processing, desalination plants, and pulp and paper industries.

Overall, the combination of corrosion resistance, high strength, and other advantageous properties makes Duplex Steel UNS S31803 pipes an attractive choice for various demanding industrial applications.

Duplex Steel UNS S31803 Pipes Specifications and Sizes

Duplex Steel UNS S31803 pipes boast a remarkable blend of austenitic and ferritic stainless steels, offering superior corrosion resistance and strength. These pipes are meticulously crafted to meet stringent industry standards, ensuring reliability in diverse applications. With sizes ranging from small diameters to large ones, they cater to varied industrial needs seamlessly. Their specifications include precise dimensions, wall thickness, and material composition, ensuring optimal performance in demanding environments.

Furthermore, the versatility of Duplex Steel UNS S31803 pipes extends to their compatibility with different welding techniques, enhancing ease of installation and maintenance. Their exceptional resistance to pitting and crevice corrosion makes them ideal for use in aggressive chemical and marine environments. Available in a range of sizes, these pipes facilitate efficient fluid transportation across industries while maintaining structural integrity and longevity. Whether in offshore platforms, chemical plants, or desalination facilities, they serve as reliable conduits for various fluids, underscoring their indispensable role in modern engineering applications.

Standard ASTM A789, A790
Outside Diameter 6-203mm
Wall Thickness 0.5-25mm
Length Up to 25m
Schedule SCH 5 to SCH XXS
Delivery Condition Pickled, Polished, Bright Annealed
Technique Seamless/Welded
Application Heat Exchanger, Heater, Condenser, Machining, Bearing Machining, API Service…
Package Woven bag, wooden case, or as per customer's requirement.
Quality Requirement Mill Test Certificate (EN 10204/3.1); Third Part Inspection is acceptable.

Types Of Duplex Stainless Steel S31803 Pipes


Duplex Steel S31803 Seamless Pipe


Duplex Steel S31803 Welded Pipe


Duplex Steel S31803 ERW Pipe


Duplex Steel S31803 EFW Pipe


Duplex Steel S31803 Square Pipe


Duplex Steel S31803 Round Pipe


Other Types Of Duplex Steel S31803 Pipes

DSS S31803 Pipes Duplex Steel S31803 Welded Pipe
Duplex Steel S31803 Thick Wall Pipe Duplex Steel S31803 Industrial Pipes
UNS S31803 Seamless Pipe UNS S31803 Duplex Steel Seamless Pipes
S31803 Duplex Stainless Steel Pipes UNS S31803 Pipe
S31803 Duplex Stainless Steel EFW Pipe Duplex Stainless Steel S31803 ERW Pipe
DSS S31803 Square Pipe Duplex Steel S31803 Rectangular Pipes
ASME SA790 Duplex Steel S31803 Pipe ASTM A790 Duplex Steel S31803 Pipes
Duplex Steel S31803 Polished Pipes Duplex Steel S31803 Cold Drawn Pipe
Duplex Steel S31803 Schedule 40 Pipe S31803 Duplex Stainless Steel Pipe

UNS S31803 Pipes Equivalent Grade

S31803 1.4462 S31803 4462-318-03-I

Duplex Steel UNS S31803 Pipes Chemical Composition

Duplex Steel UNS S31803 pipes typically exhibit a chemical composition characterized by a balanced combination of austenitic and ferritic phases. Generally, they contain around 22% chromium, 5-6% nickel, 3-4% molybdenum, and 0.1-0.3% nitrogen, enhancing their corrosion resistance and mechanical properties. Additionally, they may have small amounts of other elements such as manganese, silicon, and copper to further refine their properties. This composition grants UNS S31803 pipes excellent resistance to various corrosive environments, high strength, and good weldability, making them suitable for diverse applications in industries like oil and gas, chemical processing, and marine engineering.

UNS Designation Type Composition, % B
C Mn P S Si Cr Ni N Mo Other Elements C
S31803 . . . 0.030 2.00 0.030 0.020 1.00 21.0-23.0 4.5-6.5 0.08-0.20 2.5-3.5 . . .

Duplex Steel UNS S31803 Pipes Mechanical Properties

Duplex Steel UNS S31803 pipes exhibit excellent mechanical properties, characterized by high tensile strength, typically ranging from 620 to 800 MPa. They also possess impressive yield strength, often falling between 450 to 620 MPa. Additionally, these pipes demonstrate good elongation values, typically around 25% or more, ensuring ductility. Their superior mechanical properties make them ideal for demanding applications in various industries such as oil and gas, chemical processing, and marine engineering.

UNS Designation Type Condition Tensile Strength, min, ksi [MPa] Yield Strength,A min, ksi [MPa] Elongation in 2 in. [50 mm] or 4D, min, % Reduction of Area, min, %B,C Brinell Hardness, max
S31803 . . . annealed 90 [620] 65 [450] 25 . . . 290

Applications of Duplex Steel UNS S31803 Pipes

Duplex steel UNS S31803 pipes find applications across various industries due to their excellent combination of mechanical properties and corrosion resistance. Here are some common applications:

Oil and Gas Industry: Duplex steel pipes are widely used in oil and gas exploration, production, and refining due to their resistance to corrosion, high strength, and ability to withstand high-pressure environments.

Chemical Processing: They are used in chemical processing plants for handling corrosive fluids and gases. Duplex steel pipes can withstand the harsh conditions found in chemical processing industries, including high temperatures and corrosive environments.

Desalination Plants: In desalination plants, where seawater is converted into freshwater, duplex steel pipes are used for their resistance to chloride-induced stress corrosion cracking (SCC) and pitting corrosion.

Pulp and Paper Industry: Duplex steel pipes are employed in pulp and paper mills for transporting corrosive chemicals used in the paper-making process. Their corrosion resistance and durability make them ideal for such applications.

Marine Applications: Due to their resistance to seawater corrosion, duplex steel pipes are used in marine environments for various applications such as offshore platforms, shipbuilding, and seawater intake and outfall systems.

Water Treatment: Duplex steel pipes are utilized in water treatment plants for conveying water and chemicals. Their corrosion resistance and longevity make them suitable for this critical application.

Construction: In construction, duplex steel pipes are used for structural purposes in buildings and infrastructure where corrosion resistance and high strength are required.

Overall, duplex steel UNS S31803 pipes are versatile and find applications in industries where corrosion resistance, strength, and durability are paramount.

Electrical Industry


Automotive Industry


Construction Industry


Defence Industry


Pharmaceutical Industry


Petroleum Industry


Petrochemical Industry


Milk & Dairy Industry

Milk & Dairy

Export & Supply Destinations Of Duplex S31803 Pipes

Switzerland, Germany, Ukraine, Liechtenstein, Bulgaria, Turkey, Belarus, Greece, Belgium, Estonia, Latvia, Ireland, France, Moldova, Spain, Poland, Austria, Monaco, Malta, Luxembourg, Lithuania, Italy, Cyprus, United Kingdom, Hungary, Portugal, Norway, Romania, Finland, Netherlands, Slovakia, Serbia, Czechia/Czech Republic, Azerbaijan, Croatia, Russia, Sweden, Denmark.

Malaysia, Iraq, Bahrain, South Korea, Lebanon, Macau, Afghanistan, Oman, North Korea, Saudi Arabia, Turkey, Thailand, Azerbaijan, India, Bangladesh, Taiwan, Philippines, Mongolia, Nepal, Indonesia, British, Bhutan, United Arab Emirates, Singapore, Iran, Vietnam, Israel, Sri Lanka, Jordan, Russia, Myanmar, Kuwait, Armenia, Egypt, Qatar, China, Japan, Hong Kong, Maldives, Kyrgyzstan.

Kenya, Namibia, Mauritania, Mozambique, Ethiopia, Madagascar, Zimbabwe, Seychelles, Central African Republic, Angola, Rwanda, Zambia, Botswana, Burundi, Libya, Morocco, Senegal, Mauritius, Nigeria, Liberia, Eswatini, Gambia, Algeria, South Africa, Tunisia, Niger, Egypt, Cameroon, Uganda, Tanzania, Burkina Faso.

Haiti, El Salvador, Saint Lucia, Mexico, Canada, Belize, Trinidad and Tobago, Guatemala, Saint Vincent and the Grenadines, Costa Rica, Antigua and Barbuda, Dominican Republic, Honduras, Bahamas, Panama, Grenada, Cuba, Dominica, Jamaica, United States of America, Barbados, Nicaragua.

Argentina, Ecuador, Brazil, Paraguay, Chile, Bolivia, Venezuela, Uruguay, Colombia, Suriname, Peru, Guyana.