Super Duplex Steel Alloy 255 Industrial Valves Overview
Zeon Exports supplies Super Duplex Steel Alloy 255 (UNS S32550, Ferralium 255) industrial valves – ball, gate, globe and check types – a copper-bearing super duplex grade with a PREN above 40 and outstanding resistance to sulphuric, nitric and phosphoric acids.
Super Duplex Steel Alloy 255 Industrial Valves (Ferralium 255) control and isolate flow in the most demanding acidic and chloride process streams in chemical and offshore systems. Its 25% chromium, 5% nickel, 3.5% molybdenum composition with roughly 2% copper gives outstanding resistance to sulphuric, nitric and phosphoric acids, and copper additions provide a self-healing effect at pitting sites.
- PREN >40 with copper addition for self-healing pitting resistance
- Yield ≥550 MPa, tensile ≥760 MPa – very high strength
- EN 10204 3.1 certified, export-ready worldwide
Quick Specifications of Super Duplex Steel Alloy 255 Industrial Valves
Super Duplex Steel Alloy 255 Industrial Valves are produced to internationally recognized specifications.
| Field | Detail |
|---|---|
| Material/Grade | Super Duplex Steel Alloy 255 (Ferralium 255) |
| UNS | S32550 |
| Werkstoff Number | 1.4507 |
| Standards | ASTM A182 Gr. F61, ASTM A995 |
| Form | Ball, Gate, Globe, Check Valves |
| Finish | As specified (confirm on order) |
| Heat Treatment | Solution Annealed, water quenched |
| Certification | EN 10204 3.1 |
Equivalent Grades of Alloy 255
Alloy 255 (Ferralium 255) is recognized under several international designations below.
| UNS | Werkstoff Number | EN Steel Name | Common Trade Name | ASTM/ASME Standard |
|---|---|---|---|---|
| S32550 | 1.4507 | X2CrNiMoCuN25-6-3 | Ferralium 255 | ASTM A182 Gr. F61 / A995 |
Chemical Composition of Alloy 255
Composition per ASTM A182/A995 for UNS S32550; exact limits can vary slightly by specification and heat.
| Element | Composition (%) |
|---|---|
| Chromium (Cr) | 24.0 – 27.0 |
| Nickel (Ni) | 4.5 – 6.5 |
| Molybdenum (Mo) | 2.9 – 3.9 |
| Nitrogen (N) | 0.10 – 0.25 |
| Copper (Cu) | 1.5 – 2.5 |
| Carbon (C), max | 0.040 |
| Iron (Fe) | Balance |
Physical Properties of Super Duplex Steel Alloy 255
Physical properties for Ferralium 255, confirmed against manufacturer data.
| Property | Value |
|---|---|
| Density | 7.85 g/cm3 |
| Melting Range | Confirm against applicable datasheet |
| Magnetic Behaviour | Magnetic (ferrite phase present) |
Mechanical Properties of Super Duplex Steel Alloy 255 Industrial Valves
Minimum mechanical properties per ASTM A182/A995 for UNS S32550.
| Property | Minimum Value |
|---|---|
| Tensile Strength | 760 MPa |
| Yield Strength (0.2% offset) | 550 MPa |
| Elongation | 15% |
| Hardness | 302 HB max |
| Condition | Solution Annealed |
Corrosion Resistance of Super Duplex Steel Alloy 255
- With a PREN above 40, Super Duplex Steel Alloy 255 Industrial Valves significantly outperform standard duplex 2205 in aggressive acidic and chloride media.
- Pitting resistance: excellent resistance to chloride-induced pitting, with copper providing a self-healing effect at pit sites.
- Crevice resistance: strong performance at seat faces and stem packing.
- Chloride SCC resistance: high resistance to chloride stress corrosion cracking even in hot chloride environments.
Heat Resistance of Super Duplex Steel Alloy 255
Alloy 255 valves are generally suited to moderate continuous service temperatures typical of super duplex grades; industry guidance commonly limits continuous use to roughly 300°C to avoid embrittlement risk. Always confirm exact service limits against the governing standard and application before specifying.
Key Properties of Super Duplex Steel Alloy 255 Industrial Valves
Beyond corrosion and heat performance, Ferralium 255 valves offer these additional properties.
- Very high strength with good ductility (15% minimum elongation)
- Good weldability with matching filler metal for repairs
- Outstanding resistance to sulphuric, nitric and phosphoric acids
- Good impact toughness maintained into cold service temperatures
Benefits of Super Duplex Steel Alloy 255 Industrial Valves
Choosing Ferralium 255 valves from Zeon Exports delivers measurable advantages for your project.
- Best-in-class resistance to acidic and chloride attack combined
- Full MTC 3.1 documentation for project QA/QC requirements
- Multiple valve types and end connections to match project specs
- Reliable bulk supply with consistent ready stock
- Competitive export pricing for large industrial orders
- Fast dispatch to global project sites and ports
Related Products
Explore related Super Duplex Steel products from Zeon Exports.
Request a Quote for Super Duplex Steel Alloy 255 Industrial Valves
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Call: +91 98205 33105
Email: info@zeonexports.com
Website: www.zeonexports.com
Address: A-7/9, Saboo Building, Ardeshir Dady Cross Lane, Cawasji Patel Tank Road, Mumbai – 400004
Frequently Asked Questions About Super Duplex Steel Alloy 255 Industrial Valves
Common questions about Super Duplex Steel Alloy 255 Industrial Valves, answered below.
Q1: What is Super Duplex Steel Alloy 255 (Ferralium 255)?
Ans. Ferralium 255 (UNS S32550) is a copper-bearing super duplex stainless steel with a PREN above 40.
Q2: Which valve types are available in Alloy 255?
Ans. We supply ball, gate, globe and check valves with Alloy 255 bodies and trim.
Q3: How does Alloy 255 differ from Alloy 2507?
Ans. Alloy 255 adds roughly 2% copper for a self-healing pitting effect and strong acid resistance, versus 2507's copper-free composition.
Q4: What is the maximum service temperature?
Ans. Continuous service is generally limited to roughly 300°C; confirm exact limits against your design code.
Q5: Is Alloy 255 magnetic?
Ans. Yes, like other duplex grades, Alloy 255 is magnetic due to its ferrite phase content.
Q6: Is Alloy 255 suitable for acidic service?
Ans. Yes, Alloy 255 offers outstanding resistance to sulphuric, nitric and phosphoric acids.
Q7: What certification is provided with orders?
Ans. Every order ships with EN 10204 3.1 mill test certificates confirming grade, heat and dimensions.
Q8: Does Zeon Exports supply custom valve sizes?
Ans. Yes, valves are available in custom sizes and end connections on request for bulk industrial orders.




