Super Duplex Round Bar
Super Duplex Steel Round Bar Manufacturer, Supplier & Exporter in India
Stellar Alloys Steel Pipe & Tubes manufactures Super Duplex Round Bars in grades UNS S32750 and S32760 conforming to ASTM A276/A479 standards. Our bars deliver 800 MPa minimum tensile strength with PREN >40 for critical applications in offshore oil & gas, marine engineering, chemical processing, and desalination where standard austenitic grades fail.
We maintain ready stock of super duplex steel round bars from 3mm to 800mm diameter in hot rolled, cold drawn, and forged conditions. Every bar is supplied with Mill Test Certificate (MTC) per EN 10204 3.1 and undergoes PMI testing, hardness verification, and ultrasonic inspection before dispatch. Production capacity: 500 tonnes/month.
Available forms include round bar, bright bar, flat bar, hex bar, square bar, and forged bar. We cut to length, machine to specification, and export worldwide with full material traceability. ISO 9001:2015 certified facility with in-house testing laboratory.
Manufacturing & Quality Infrastructure
Our 15,000 sq.ft manufacturing facility operates 24/7 production with capacity to forge and machine super duplex bars up to 800mm diameter. In-house capabilities include:
- Hot forging press: 500-ton capacity for bars 50mm-800mm
- Cold drawing lines: Bright bar production 3mm-50mm with Ra 0.8 surface finish
- CNC machining: Tolerance holding to H7/H8 with straightness 0.5mm/meter
- Testing lab: PMI spectrometer, Vickers hardness tester, 50-ton UTM, ultrasonic flaw detector
ISO 9001:2015 and PED 2014/68/EU certified. NACE MR0175/ISO 15156 compliance available. Average lead time: 3-4 weeks for standard sizes, 6-8 weeks for custom forgings.
Table of Contents
- What are Super Duplex Steel Round Bars
- Super Duplex Steel Round Bar Specifications
- Types of Super Duplex Steel Bars We Supply
- Super Duplex Steel Round Bar Material Grades
- Super Duplex Steel Round Bar Size Chart
- Super Duplex Steel Round Bar Weight Chart
- Super Duplex Steel Round Bars Price List
- Chemical Composition of Super Duplex Steel Round Bars
- Mechanical Properties of Super Duplex Steel Bars
- Heat Treatment Process
- Available Surface Finish
- Features of Super Duplex Steel Round Bars
- Super Duplex Steel Round Bar Equivalent Grades
- Super Duplex Steel Round Bar Applications
- Testing & Quality Assurance
- Packaging & Delivery
- Why Choose Steel Pipe & Tubes?
- FAQs - Super Duplex Steel Round Bar
What are Super Duplex Steel Round Bars
Super Duplex Steel is a high alloy stainless steel containing a balanced microstructure of ferrite and austenite, providing superior corrosion resistance and high tensile strength. Compared to conventional stainless steels, Super Duplex Steel offers better chloride corrosion resistance, higher yield strength, and improved fatigue resistance.
Performance Advantages Over Standard Grades:
- Corrosion Resistance: PREN >40 (vs 316L at ~24) provides immunity to pitting and crevice corrosion in chloride environments up to 300°C. Critical for seawater, brine, and acidic gas applications.
- Mechanical Strength: Yield strength 550 MPa minimum (vs 316L at 220 MPa) allows thinner wall sections, reducing material cost while maintaining structural integrity.
- Stress Corrosion Cracking: Duplex microstructure provides immunity to chloride SCC up to 250°C, whereas austenitic grades fail above 80°C in marine environments.
- Weldability: Pre-heat not required. Post-weld heat treatment is unnecessary for thin sections. Maintains corrosion resistance in heat-affected zone with proper filler selection (ER2594/ER2595).
Super Duplex Steel Round Bar Specifications
Specification | Details |
Product Name | Super Duplex Steel Round Bar |
Material Grade | UNS S32750 / UNS S32760 |
Standard | ASTM A276 / ASTM A479 |
Size Range | 3mm to 800mm |
Form | Round, Square, Flat, Hex, Rectangular |
Length | 3 Meter to 6 Meter |
Finish | Bright, Black, Polished, Rough Turned |
Manufacturing Process | Hot Rolled, Cold Drawn, Forged |
Hardness | ≤ 300 HB |
Density | 7.8 g/cm³ |
Melting Point | 1350°C |
Tolerance | H8, H9, H11 |
Condition | Annealed, Hardened & Tempered |
Surface Finish | 6RA, 32RA, 63RA |
Types of Super Duplex Steel Bars We Supply
We manufacture stainless steel round bars in multiple grades and finishes to meet diverse industrial requirements:
Super Duplex Round Bar
Super Duplex Bright Bar
Super Duplex Flat Bar
Super Duplex Square Bar
Super Duplex Hex Bar
Super Duplex Forged Bar
Super Duplex Hollow Bar
Super Duplex Threaded Bar
Super Duplex Steel Round Bar Material Grades
Super Duplex S32750 Round Bars
Super Duplex S32760 Round Bars
Super Duplex Steel Round Bar Size Chart
Diameter | Metric Size | Available Form | Length |
3mm – 10mm | Small Diameter | Bright Bar / Polished Bar | 3M / 6M |
12mm – 25mm | Medium Diameter | Round Bar / Black Bar | 3M / 6M / Cut Length |
26mm – 50mm | Heavy Section | Forged Bar / Hot Rolled | Custom Length |
51mm – 100mm | Large Diameter | Forged Round Bar | Custom Length |
101mm – 300mm | Extra Large | Forged & Machined Bar | As Required |
301mm – 800mm | Jumbo Size | Forged Round Bar | Custom |
Super Duplex Steel Round Bar Weight Chart
Size (mm) | Weight Per Meter (Approx.) |
10mm | 0.62 Kg |
12mm | 0.89 Kg |
16mm | 1.58 Kg |
20mm | 2.47 Kg |
25mm | 3.85 Kg |
32mm | 6.31 Kg |
40mm | 9.86 Kg |
50mm | 15.42 Kg |
65mm | 26.06 Kg |
75mm | 34.67 Kg |
100mm | 61.65 Kg |
Super Duplex Steel Round Bars Price List
Product Description | Size | Price (Approx.) |
Super Duplex S32750 Round Bar | 10mm – 25mm | ₹650 – ₹850 Per Kg |
Super Duplex S32760 Round Bar | 10mm – 25mm | ₹750 – ₹950 Per Kg |
Super Duplex Bright Bar | 6mm – 50mm | ₹700 – ₹1000 Per Kg |
Super Duplex Forged Bar | 50mm – 300mm | ₹850 – ₹1200 Per Kg |
ASTM A276 S32750 Round Bar | All Sizes | On Request |
ASTM A276 S32760 Round Bar | All Sizes | On Request |
Note: Prices may vary depending on quantity, size, finish, raw material cost, and market conditions.
Chemical Composition of Super Duplex Steel Round Bars
Element | UNS S32750 (%) | UNS S32760 (%) |
Chromium | 24 – 26 | 24 – 26 |
Nickel | 6 – 8 | 6 – 8 |
Molybdenum | 3 – 5 | 3 – 4 |
Carbon | 0.03 Max | 0.03 Max |
Nitrogen | 0.24 – 0.32 | 0.20 – 0.30 |
Copper | — | 0.50 – 1.00 |
Tungsten | — | 0.50 – 1.00 |
Mechanical Properties of Super Duplex Steel Bars
- Solution Annealing: Super duplex bars are solution annealed at 1020-1100°C followed by rapid water quenching to achieve balanced ferrite-austenite microstructure (40-60% ferrite). This process ensures maximum corrosion resistance and mechanical properties.
- Critical Temperature Control: Exposure to 300-1000°C during fabrication or service can precipitate sigma phase and chromium nitrides, severely reducing corrosion resistance and toughness. Welding and forming operations require controlled interpass temperatures below 200°C.
- Post-Weld Treatment: Solution annealing recommended for heavy section welds (>25mm) to restore corrosion resistance in heat-affected zones. Not required for thin sections with proper welding procedures.
Available Surface Finish
- Bright Finish
- Black Finish
- Polish Finish
- Rough Turned Finish
- Matt Finish
- Cold Drawn Finish
- Hot Rolled Finish
Our stainless steel round bars serve mission-critical applications across multiple industries due to their exceptional strength, corrosion resistance, and reliability in harsh environments:
Common applications include:
- Oil and Gas Industry – Downhole pump shafts, valve stems, instrumentation components, and wellhead equipment
- Chemical Processing Plants – Reactor vessel shafts, agitator components, pump impellers, and corrosion-resistant fasteners
- Marine and Offshore Structures – Propeller shafts, deck equipment, rigging hardware, and saltwater-resistant fittings
- Automotive and Mechanical Engineering – Engine components, transmission shafts, precision machined parts, and suspension elements
- Pump and Valve Manufacturing – Valve stems, pump shafts, piston rods, and high-pressure fittings
- Construction and Structural Frameworks – Architectural supports, railing systems, and load-bearing structural members
- Food Processing Equipment – Mixer shafts, conveyor components, sanitary fittings, and hygienic processing machinery
- Aerospace Components – Landing gear parts, high-strength fasteners, precision machined aircraft components
Features of Super Duplex Steel Round Bars
- High Strength: Super Duplex Steel has nearly double the yield strength compared to conventional austenitic stainless steels, making it suitable for demanding industrial applications.
- Excellent Corrosion Resistance: These bars provide outstanding resistance to pitting corrosion, crevice corrosion, and chloride-induced stress corrosion cracking.
- Superior Durability; Super Duplex Steel Round Bars deliver exceptional performance in harsh marine and chemical environments.
- Excellent Weldability; The balanced ferritic-austenitic structure ensures excellent fabrication and welding properties.
- Cost Effective Solution: Higher strength allows the use of thinner sections, reducing overall weight and material costs.
Super Duplex Steel Round Bar Equivalent Grades
Standard | Grade |
UNS | S32750 / S32760 |
WERKSTOFF NR | 1.4410 |
ASTM | A276 |
EN | X2CrNiMoN25-7-4 |
Super Duplex Steel Round Bar Applications
Super Duplex Steel Bars are widely used in various industrial applications such as:
- Oil & Gas Sector: Subsea manifold components, pipeline connectors, and wellhead equipment operating at pressures up to 200 bar in H2S-containing environments. S32760 grade specified for critical pressure-containing components per NORSOK M-650.
- Marine & Offshore: Propeller shafts, pump shafts, and fasteners for naval vessels and offshore platforms. Superior performance in seawater (3.5% NaCl) compared to 316L which experiences pitting failure within 6-12 months.
- Chemical Processing: Agitator shafts, heat exchanger tubes, and reactor components handling bleach, chlorine dioxide, and acidic chloride solutions where austenitic grades corrode rapidly.
- Desalination Plants: Reverse osmosis system components, high-pressure pump shafts, and valve stems. Material selection critical for 25+ year service life in concentrated brine at elevated temperatures.
Testing & Quality Assurance
We conduct comprehensive testing to verify material compliance and structural integrity:
Testing Methods:
- PMI Testing – Positive Material Identification via XRF spectrometry
- Hardness Testing – Brinell and Vickers per ASTM E10/E92
- Flattening Test – Per ASTM A370 for ductility verification
- Ultrasonic Testing – Per ASTM A388 for internal defect detection
- Micro & Macro Test – Metallographic examination of grain structure
- Spectro Analysis – Chemical composition verification
- Intergranular Corrosion Test – Per ASTM A262 Practice E
- Third Party Inspection – Independent verification available (TÜV, Lloyd’s, Bureau Veritas)
Documents Supplied:
- Mill Test Certificate (MTC) per EN 10204 3.1
- Heat Treatment Charts with time-temperature records
- Fumigation Certificate for export shipments
- NABL Approved Test Reports (destructive testing)
- Quality Assurance Plan (project-specific)
Packaging & Delivery
Super Duplex Steel Round Bars are packaged using export-compliant materials to prevent handling damage and corrosion during transit. Each bundle is identified with heat number tags and material grade stickers.
Fast delivery across India via road transport. International export to UAE, Saudi Arabia, Qatar, Oman, Kuwait, Singapore, Malaysia, South Africa, Europe, and USA. Complete export documentation including Commercial Invoice, Packing List, Bill of Lading, Certificate of Origin, and material test certificates.
Why Choose Steel Pipe & Tubes?
- Ready stock availability – 3mm to 800mm diameter in multiple grades
- Competitive pricing with transparent quotations within 24 hours
- Fast delivery – 3-4 weeks standard, 6-8 weeks custom forgings
- Custom sizes and machining to your specifications
- ISO 9001:2015 and PED 2014/68/EU certified manufacturing
- Experienced metallurgical team with 15+ years in duplex alloys
- Worldwide export network with proven track record
- Third party inspection welcome (TÜV, Lloyd’s, Bureau Veritas)
- 100% material traceability with heat number marking
- Technical support for material selection and application engineering
FAQs - Super Duplex Steel Round Bar
Super Duplex Steel Round Bar is a high-strength stainless steel bar with balanced ferrite-austenite microstructure, offering superior corrosion resistance (PREN >40) and double the yield strength of austenitic grades. Used in offshore, marine, chemical, and oil & gas applications.
ASTM A276 is the standard specification covering hot-finished and cold-finished stainless steel bars and shapes, including Super Duplex Steel grades UNS S32750 (2507) and UNS S32760 (Zeron 100). It defines chemical composition, mechanical properties, and testing requirements.
UNS S32760 contains 0.5-1.0% copper and 0.5-1.0% tungsten additions not present in S32750. These elements enhance crevice corrosion resistance, making S32760 superior for subsea applications and high-chloride environments above 150°C.
Yes. Super Duplex (PREN >40) provides significantly better pitting and crevice corrosion resistance than standard Duplex 2205 (PREN ~35). Super Duplex maintains mechanical properties at higher temperatures (up to 250°C vs 150°C) and resists chloride stress corrosion cracking in more severe environments.
Prices range from ₹650-₹1200 per kg depending on grade (S32750 vs S32760), diameter (small vs large forgings), finish (hot rolled vs bright bar), quantity ordered, and current nickel/molybdenum raw material costs. Request formal quotation for project-specific pricing.
We supply Super Duplex Steel Round Bars from 3mm to 800mm diameter. Small diameters (3-50mm) available as cold drawn bright bar. Medium sections (50-100mm) in hot rolled. Large forgings (100-800mm) produced via hot forging and machining. Custom lengths up to 6 meters standard, longer lengths on request.