Duplex Steel Plates, Duplex Stainless Steel Plate, Duplex stainless steel plates stockist Mumbai, Duplex Steel Plates Suppliers
Duplex stainless steel plates combine austenitic and ferritic structures within a single material. This dual-phase microstructure delivers high mechanical strength alongside strong corrosion resistance, a combination most standalone stainless grades cannot match. Standard grades sacrifice one property for the other. That gap is exactly why duplex plates work in the harshest service conditions, and why Calico Metal Alloys LLP operates as a duplex stainless steel plates stockist in Mumbai, serving refineries, offshore platforms, and fabrication units across India.
Refinery expansions and offshore projects along Gujarat, Maharashtra, and the eastern coastline have pushed demand for duplex plates sharply upward. Pipelines, pressure vessels, and heat exchangers in these plants face constant chloride exposure under high pressure. Standard 304 or 316 grades corrode fast under that load. Duplex plates hold up. Being a duplex stainless steel plate stockist, we keep multiple grades in stock to match project timelines without delay.
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 strength, duplex plates reach nearly double the yield strength of standard austenitic grades. Fabricators use thinner plates for the same structural load, cutting material weight and cost across large projects. Where replacement means shutting down a plant, that strength advantage changes the economics entirely.
Calico Metal Alloys LLP operates as a duplex steel plates supplier, sourcing every plate from established mills and testing each batch against international standards. Our stock moves fast, so orders ship without the delays that stall fabrication schedules. Whether a project calls for a specific grade, thickness, or certification package, our technical team matches the plate to the application before it leaves the warehouse.
Table of Content
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
Duplex Steel 2205 is one of the most commonly used duplex stainless steel grades, offering a balanced combination of strength and corrosion resistance. It is available in two closely related specifications,Duplex Steel UNS S31803 Plates and Duplex Steel UNS S32205 Plates, with approximately 22% chromium, 3% molybdenum, and nitrogen additions. These plates provide good resistance to stress corrosion cracking, pitting, and crevice corrosion. Due to their mechanical strength and corrosion-resistant properties, Duplex Steel 2205 Plates are widely used in pressure vessels, heat exchangers, chemical storage tanks, and offshore structural applications.
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
Available Sizes, Dimensions and Customisation
| Parameter | Available Options |
| Plate Width | 1000 mm – 2500 mm |
| Plate Length | 2000 mm – 6000 mm |
| Thickness | 0.5 mm – 150 mm |
| Standard Sizes | 1000 × 2000 mm, 1220 × 2440 mm, 1500 × 3000 mm, 2000 × 4000 mm |
| Custom Width & Length | Available as per customer requirements |
| Custom Thickness | Available as per application requirements |
| Surface Finish | Hot Rolled, Pickled & Annealed, Polished |
| Edge Condition | Mill Edge, Trimmed Edge |
| Cutting | Shearing, Plasma Cutting, Laser Cutting |
| Material Grades | Duplex 2205, Super Duplex 2507 and other grades |
| Customization | Size, thickness, cutting and finish can be customized |
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. For grade-wise pricing and available material options, refer to our Duplex Steel Price List.
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 are Duplex Steel Plates?
Duplex steel plates are flat products that contain roughly equal parts austenite and ferrite, giving them higher strength and better chloride resistance than standard stainless grades.
What grades of Duplex Stainless Steel Plates do you supply?
We stock UNS S31803, S32205, S32750, and S32760, along with Lean Duplex 2101 and SMO 254 on request.
What sizes are available for Duplex Stainless Steel Plates?
The sizes available for Duplex Steel Plates are from 3mm to 100mm in thickness, with widths up to 2500mm and custom cutting available against project drawings.
What standards do your Duplex Steel Plates comply with?
Our Duplex Steel Plates comply with ASTM A240, ASME SA240, and EN 10088 standards.
Can Duplex Steel Plates be fabricated and welded?
Yes, duplex plates can be welded using matching filler metal and controlled heat input so as to retain the phase balance during fabrication.
Why choose Calico Metal Alloys LLP as your Duplex Steel Plates supplier?
You should choose Calico Metal Alloys LLP as your Duplex Steel Plates supplier because our ISO 9001:2015 certification, stocked inventory and same week dispatch from Mumbai ensures that client projects are on schedule and do not suffer from sourcing delays.
