Duplex Steel Pipe

Backed by a team of experienced professionals and a state-of-the-art infrastructure, we ensure that our Duplex Steel Pipes conform to international standards and deliver optimal performance in demanding environments. At Calico Metal Alloys LLP, we prioritise customer satisfaction, offering top-notch products that exemplify precision and excellence.

A Duplex Steel Pipe is a type of pipe made from duplex stainless steel. Duplex stainless steel has a two-phase microstructure consisting of roughly equal proportions of austenite and ferrite phases. This combination of phases provides several advantageous properties, including high strength, excellent corrosion resistance, and good weldability.

Table of Content

• Duplex Pipes Manufacturing Process
• Duplex Steel Pipes Specifications
• Types Of Duplex Steel Pipes
• Other Types Of Duplex Steel Pipes
• Duplex Pipes Industrial Application
• Export & Supply Destination of Duplex Pipes

Manufacturing Process Of Duplex 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.

Duplex steel pipes are commonly used in various industries requiring corrosion resistance and high strength, such as oil and gas, chemical processing, marine environments, and desalination plants.

Specifications of Duplex Steel Pipes

Duplex Pipe specifications may vary depending on the specific application and industry standards, but some common specifications include:

Material Grade: Duplex steel pipes are typically available in various material grades, such as ASTM A790 UNS S31803 (Duplex 2205), ASTM A790 UNS S32205, ASTM A789 UNS S31803, ASTM A789 UNS S32205, and others.

Size: Duplex steel pipes are available in a wide range of sizes, ranging from small-diameter pipes used in plumbing applications to large-diameter pipes used in industrial applications.

Wall Thickness: The wall thickness of duplex steel pipes can vary depending on the pressure and temperature requirements of the application. Common wall thicknesses include Schedule 10, Schedule 40, Schedule 80, and others.

Length: Duplex steel pipes are typically available in standard lengths of 6 meters or 20 feet. However, custom lengths can also be manufactured according to specific requirements.

End Connections: Duplex steel pipes can be supplied with various end connections, including plain ends, beveled ends, threaded ends, and socket weld ends. The choice of end connection depends on the piping system's requirements and the installation method.

Surface Finish: Duplex steel pipes are available in various surface finishes, including annealed, pickled, polished, and others, depending on the application requirements.

Standards: Duplex steel pipes are manufactured according to various international standards, such as ASTM (American Society for Testing and Materials), ASME (American Society of Mechanical Engineers), EN (European Norm), and others.

Types Of Duplex Stainless Steel Pipes

01

Duplex Steel Seamless Pipe

02

Duplex Steel Welded Pipe

03

Duplex Steel ERW Pipe

04

Duplex Steel EFW Pipe

05

Duplex Steel Square Pipe

06

Duplex Steel Round Pipe

Other Types Of Duplex Steel Pipes

Equivalent of Duplex Steel Pipes

Equivalent grades of duplex steel pipes refer to other materials that have similar chemical composition and mechanical properties, allowing them to be used interchangeably in certain applications. Some commonly used equivalent grades of duplex steel pipes include:

ASTM A790/A789 UNS S31803/UNS S32205 (Duplex 2205): Equivalent grades: EN 1.4462, X2CrNiMoN22-5-3, 2205, F51

These equivalent grades are recognized internationally and comply with various industry standards. It's essential to verify the specific requirements of your application and consult with a materials engineer or supplier to ensure the suitability of the chosen equivalent grade for your project.

Chemical Composition of Duplex Steel Pipes

Duplex steel pipes, renowned for their exceptional corrosion resistance and high strength, boast a distinctive two-phase microstructure featuring approximately equal proportions of austenite and ferrite phases. The chemical composition of duplex steel pipes, exemplified by ASTM A790/A789 UNS S31803/UNS S32205 (Duplex 2205), typically includes elements that contribute to these favorable characteristics.

The primary elements in Duplex 2205 are chromium (21-23%), nickel (4.5-6.5%), molybdenum (2.5-3.5%), and nitrogen (0.08-0.20%). These alloying elements enhance the corrosion resistance and overall durability of the steel. Additionally, the dual-phase structure provides a combination of properties, such as improved stress corrosion cracking resistance, higher yield strength, and excellent toughness, making duplex steel pipes suitable for various demanding applications.

Mechanical Properties of Duplex Steel Pipes

The dual-phase structure imparts a combination of excellent mechanical properties to duplex steel pipes. Here are some key mechanical properties of duplex steel pipes:

Strength: Duplex steel pipes exhibit high strength, which is a result of the combination of austenitic and ferritic phases. This makes them stronger than both austenitic and ferritic stainless steels. The strength of duplex steel pipes contributes to their ability to withstand high-pressure and corrosive environments.

Corrosion Resistance: Duplex stainless steels are known for their excellent corrosion resistance. They provide good resistance to both general corrosion and localized corrosion, such as pitting and crevice corrosion. This makes duplex steel pipes suitable for use in aggressive environments, including those containing chloride ions.

Weldability: Duplex steels are weldable, but it's important to follow proper welding procedures to maintain the desired properties. Welding can affect the balance of the austenitic and ferritic phases, and precautions should be taken to avoid the formation of detrimental phases or microstructures.

Temperature Resistance: Duplex steel pipes maintain their mechanical properties over a wide range of temperatures. This makes them suitable for applications in both high and low-temperature environments.

Duplex Steel Pipes Industrial Application

Electrical

Automotive

Construction

Defence

Pharmaceutical

Petroleum

Petrochemical

Milk & Dairy

Export & Supply Destinations Of Duplex Pipes