Duplex Steel Plates, Duplex Stainless Steel Plate, Duplex stainless steel plates stockist Mumbai, Duplex Steel Plates Suppliers
Duplex stainless steel plates are produced by mixing austenitic and ferritic stainless steel structures into one material. That dual-phase microstructure gives the plates both high mechanical strength and good corrosion resistance at the same time. Standard stainless steel grades typically offer one or the other, not both. That is what makes duplex plates more suitable for harsh service conditions.
With the growth in refinery and offshore projects in Gujarat, Maharashtra and the eastern coastline, the oil and gas sectors in India have witnessed a huge demand for duplex stainless steel plates. In such environments, pipelines, pressure vessels and heat exchangers are constantly exposed to chlorides and operate under high pressures. Standard stainless grades won't cut it for that combination.
What are Duplex Stainless Steel Plates?
Duplex stainless steel plates carry close to equal shares of austenite and ferrite in their microstructure, a balance single-phase grades never achieve. Chromium content runs between 22% and 25%, backed by controlled molybdenum and nitrogen additions. These elements resist pitting and crevice corrosion far better than 304 or 316 can manage.
On the mechanical side, duplex plates carry close to double the yield strength of standard austenitic grades. That means thinner plates can be used for the same structural requirement, which reduces material weight and cost across large fabrication projects. For applications where replacement is expensive and downtime matters, duplex plates are the more practical option.
Table of Content
- Duplex Plates Manufacturing Process
- Types & Grades Of Duplex Steel Plates
- Technical Specifications of Duplex Steel Plates
- Key Features & Advantages
- Duplex Plate Industrial Application
- Duplex Plates For Oil & Gas Industry in India
- Available Sizes & Customisation
- Export & Supply Destination of Duplex Plate
- Frequently Asked Questions
Manufacturing Process Of Duplex Plates
The process begins with the choice of raw materials and alloying. Chromium, nickel, molybdenum and nitrogen proportions are closely controlled as any variation will affect the final microstructure and mechanical behaviour.
Steel is melted in an electric arc furnace and refined by argon oxygen decarburisation. It reduces the carbon content and changes the chemistry of the alloy before the casting. Cast slabs are then hot rolled to the target thickness. Cold rolling follows, where tighter tolerances or smoother surfaces are needed.
Solution annealing comes after rolling. Plates are heated and then water-quenched rapidly to restore the balanced duplex microstructure and recover corrosion resistance in areas affected by working. After annealing, plates are pickled, finished to the specified surface condition, and inspected for dimensions, mechanical properties, and chemical composition before dispatch.
Types and Grades of Duplex Steel Plates
Duplex Steel 2205 Plates
2205 is the most widely used duplex grade. It is based on UNS S31803 and S32205 with about 22% chromium, 3% molybdenum plus nitrogen additions. The grade is good in resistance to stress corrosion cracking, pitting and crevice corrosion. It is used across pressure vessels, heat exchangers, chemical tanks, and offshore structural components.
Super Duplex Steel Plates
Super duplex grades carry higher alloy content. Chromium is at 25%, molybdenum at 3.5 to 4%, and nitrogen is elevated compared to the standard duplex. Grades include UNS S32750 (2507) and S32760. These are better suited for seawater service, aggressive chemical environments, and subsea equipment where chloride concentrations are higher than standard duplex can handle reliably.
Lean Duplex Steel Plates
Lean duplex grades contain less nickel and are more economical for applications where full duplex performance is not necessary. Grades like UNS S32101 and S32304 are used for structural fabrication and storage tanks where service conditions are less aggressive.
Custom Duplex Steel Plate Grades
Project-specific grades are sourced based on composition, tolerance, and testing requirements. Cut-to-size, edge preparation, and fabrication support are available on request.
Technical Specifications of Duplex Steel Plates
The common parameters of duplex stainless steel plates offered by Calico Metal Alloys LLP are as follows.
| Parameter | Specification |
|---|---|
| Material Grades | Duplex 2205, Super Duplex 2507, Lean Duplex |
| Standards | ASTM A240 / ASME SA240 |
| Thickness Range | 3 mm to 100 mm |
| Width Range | 1000 mm to 2500 mm |
| Length Range | 2000 mm to 12000 mm |
| Surface Finish | Hot Rolled, Cold Rolled, Polished |
| Form | Plates, Sheets, Coils |
| Hardness | Varies by grade |
| Corrosion Resistance | Excellent |
| Weldability | Very Good |
Key Features and Advantages of Duplex Steel Plates
High Corrosion Resistance
- Resistant to pitting, crevice corrosion, and stress corrosion cracking
- Suitable for offshore, chemical, and seawater handling applications
Superior Mechanical Strength
- Yield strength close to double that of standard 304 or 316 grades
- Thinner plate usage is possible, reducing overall material cost
Excellent Weldability
- Compatible with TIG, MIG, and submerged arc welding
- Corrosion resistance is maintained in weld zones when the correct procedures are followed
High Temperature and Pressure Resistance
- Performs under elevated pressure and temperature conditions
- Suited for boilers, condensers, and pressure vessels in oil refining and power generation
Long Service Life
- Duplex microstructure contributes to longer service before replacement is needed
- Reduces maintenance costs and unplanned downtime in critical installations
Cost Efficiency
- High strength-to-weight ratio reduces the volume of material required
- Lower fabrication and transport costs on large-scale projects
Chemical Composition of Duplex Steel Plates
Standard chemical composition for Duplex 2205, the most common grade in industrial supply.
| Element | Duplex 2205 (%) |
|---|---|
| Chromium | 22.0 – 23.0 |
| Nickel | 4.5 – 6.5 |
| Molybdenum | 3.0 – 3.5 |
| Nitrogen | 0.14 – 0.20 |
| Carbon | 0.03 Max |
| Iron | Balance |
Mechanical Properties of Duplex Steel Plates
Typical mechanical values for Duplex 2205 grade plates per ASTM A240 / ASME SA240 is listed in the table given below.
| Property | Value |
| Tensile Strength | 620 MPa Min |
| Yield Strength | 450 MPa Min |
| Elongation | 25% Min |
| Hardness | 293 HB Max |
| Density | 7.8 g/cm³ |
Applications of Duplex stainless steel plates
Duplex Steel Plates are specified in the below mentioned high-performing industries.
Oil and Gas Industry
- Offshore production platforms and subsea equipment
- Pressure vessels and pipeline systems
- Heat exchangers in refineries
- Duplex stainless steel plates for oil and gas in India are seeing rising demand as domestic refining and LNG projects expand
Chemical Processing Industry
- Chemical storage tanks and reactors
- Process equipment in fertiliser and petrochemical plants
Marine and Shipbuilding
- Seawater handling systems and desalination equipment
- Marine structural components and ballast tanks
Power Generation
- Boilers, condensers, and turbine components
Construction and Infrastructure
- Structural fabrication, bridges, and industrial buildings in coastal or chemically exposed locations
Duplex Steel Plates for Oil and Gas Industry in India
Offshore platforms, subsea pipelines, and onshore refineries in India operate under chloride-rich, high-pressure conditions. Standard stainless steel grades are prone to stress corrosion cracking and pitting in these environments, which leads to early failures and unplanned shutdowns.
Duplex grades like 2205 and 2507 are more reliable under these conditions. The chromium and molybdenum content builds up a passive film that is resistant to pitting and crevice corrosion. Higher yield strength also means fewer welds in pipeline fabrication, and fewer welds mean fewer potential points of failure.
Domestic refining capacity has increased, and projects in Gujarat, Maharashtra, and the eastern coastline have moved to duplex grades. These materials procurement has also been increased by LNG terminal projects and offshore field development.
As a duplex stainless steel plates stockist in India, Calico Metal Alloys LLP supplies duplex 2205 and super duplex 2507 with mill test certificates and third-party inspection support for oil and gas applications.
Available Sizes, Dimensions and Customisation
Standard stock covers thicknesses from 3 mm to 100 mm, widths from 1000 mm to 2500 mm, and lengths from 2000 mm to 12000 mm. Non-standard dimensions can be cut to size, minimising cutting on site and waste of material.
Surface finishes include hot rolled, cold rolled, and polished. Pressure vessel and pipeline fabrication requirements are catered for with edge preparation, such as bevelling. If you have special tolerances or other testing requirements apart from normal certification, we will work directly with mills and inspection agencies.
Why Choose Us as Duplex Stainless Steel Plates Stockist in Mumbai?
Calico Metal Alloys LLP, a stockist of duplex stainless steel plates in Mumbai, is ISO 9001:2015 certified. Most orders ship without delay as we keep ready stock in duplex 2205, super duplex 2507, and lean duplex grades in standard dimensions. Mill supply is coordinated with fixed delivery schedules for larger volumes or non-standard specifications.
All supplies are accompanied by mill test certificates covering chemical composition and mechanical properties data. Where necessary third party inspection reports are arranged. Prices are competitive, particularly for bulk orders and long term projects.
Our supply reach covers Maharashtra, Gujarat, Rajasthan, Tamil Nadu, and Andhra Pradesh. Export supply to Gulf and Southeast Asian markets is also handled with full documentation. As a duplex stainless steel plates stockist in India, we cover fabrication, cut-to-size, edge preparation, and technical consultation for grade selection at the enquiry stage.
Electrical
Automotive
Construction
Defence
Pharmaceutical
Petroleum
Petrochemical
Milk & Dairy
Export & Supply Destinations Of Duplex Plates
Austria, Azerbaijan, Belarus, Belgium, Bulgaria, Croatia, Cyprus, Czechia/Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Liechtenstein, Lithuania, Luxembourg, Malta, Moldova, Monaco, Netherlands, Norway, Poland, Portugal, Romania, Russia, Serbia, Slovakia, Spain, Sweden, Switzerland, Turkey, Ukraine, United Kingdom.
Afghanistan, Armenia, Azerbaijan, Bahrain, Bangladesh, Bhutan, China, Egypt, Hong Kong, India, Indonesia, Israel, Japan, Jordan, Kuwait, Kyrgyzstan, Lebanon, Macau, Malaysia, Maldives, Mongolia, Myanmar, Nepal, Oman, Philippines, Qatar, Russia, Saudi Arabia, Singapore, South Korea, Sri Lanka, Taiwan, Thailand, Turkey, United Arab Emirates, Vietnam.
Algeria, Angola, Botswana, Burkina Faso, Burundi, Cameroon, Central African Republic, Egypt, Eswatini, Ethiopia, Gambia, Kenya, Liberia, Libya, Madagascar, Mauritania, Mauritius, Morocco, Mozambique, Namibia, Niger, Nigeria, Rwanda, Senegal, Seychelles, South Africa, Tanzania, Tunisia, Uganda, Zambia, Zimbabwe.
Antigua and Barbuda, Bahamas, Barbados, Belize, Canada, Costa Rica, Cuba, Dominica, Dominican Republic, El Salvador, Grenada, Guatemala, Haiti, Honduras, Jamaica, Mexico, Nicaragua, Panama, Saint Lucia, Saint Vincent and the Grenadines, Trinidad and Tobago, United States of America.
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Guyana, Paraguay, Peru, Suriname, Uruguay, Venezuela.
Frequently Asked Questions
What industries use Duplex stainless steel plates?
Mainly Oil & Gas, chemical processing, marine, power generation, and structural construction. These are the areas where corrosion resistance and high mechanical strength are required simultaneously.
Are Duplex stainless steel plates available in custom sizes?
Yes. Custom thickness, width, length, edge preparation, and surface finish are available. Plates are cut to size to meet project requirements.
Do Duplex stainless steel plates come with mill test
certificates?
Yes. All plates are supplied with mill test certificates for chemical composition and mechanical properties to ASTM A240 / ASME SA240 or other applicable standards.
Are Duplex stainless steel plates suitable for corrosive
environments?
Yes. Duplex grades resist pitting, crevice corrosion, and stress corrosion cracking in chloride-rich, acidic, and high-pressure environments where standard stainless grades fall short.
Do you supply Duplex stainless steel plates for export
projects?
Yes. Supply includes full export documentation, such as test certificates and packing lists, covering Gulf countries and Southeast Asian markets.
