AISI 2507 Super-Duplex Stainless Steel: Propiedades, Fabricación & Guía de aplicaciones

AISI 2507 super-duplex stainless steel is the gold standard for extreme corrosion resistance and high strength. es unico2507 ferrite-austenite balance 50-50 microstructure and ultra-high2507 PREN ≥ 40 make it ideal for the harshest environments—from deep-sea oil rigs to chemical processing plants. Esta guía desglosa sus especificaciones clave., actuación, y usos del mundo real para ayudarle a seleccionarlo con confianza.

1. Descripción general de materiales & Especificaciones clave

Understanding 2507’s composition and standards is critical to unlocking its full potential. A continuación se muestra un desglose claro de sus propiedades esenciales..

Composición química & Estándares

El2507 super-duplex composition is engineered for strength and corrosion resistance: 24–26% chromium, 6–8% nickel, 3–5% molybdenum, and 0.24–0.32% nitrogen. These elements create its balanced microstructure and high PREN. It adheres to global standards:

• 2507 UNS S32750 (Sistema de numeración unificado)
• 2507 EN 1.4410 equivalente (Estándar europeo para igualar el rendimiento)
• 2507 ASTM A240 / 2507 ASME SA-240 (para platos, hojas, y tiras)

Físico & Propiedades mecánicas

2507 delivers exceptional strength—far higher than standard duplex or austenitic alloys. Las métricas clave están organizadas en la siguiente tabla.:

A Norwegian offshore company uses2507 ASTM A240 plates for subsea manifolds—they rely on the 550 MPa yield strength to handle 400 bar deep-sea pressure and corrosive seawater.

2. Resistencia a la corrosión & Desempeño ambiental

2507’s biggest advantage is its industry-leading corrosion resistance. Es2507 PREN 41–45 (Pitting Resistance Equivalent Number) is far higher than 2205’s PREN of 35–40, making it nearly immune to pitting, crevice corrosion, and stress cracking in harsh fluids.

Rasgos clave de resistencia a la corrosión

• Pitting & Crevice Corrosion: It has unmatched 2507 pitting corrosion resistance and a high 2507 crevice corrosion threshold—even in tight gaps (p.ej., heat exchanger gaskets) exposed to 60 °C seawater.
• Stress Corrosion Cracking: It offers 2507 chloride stress corrosion cracking immunity—critical for desalination plants and offshore pipelines where chloride levels exceed 10,000 ppm.
• Sour Service: It meets 2507 sour service NACE MR0175 / ISO 15156 estándares, resisting 2507 sulfide stress cracking in oil wells with high hydrogen sulfide (H₂S) levels.
• Resistencia química: Se encarga 2507 sulfuric acid resistance (resists 30% sulfuric acid up to 50 °C) and has higher 2507 hydrochloric acid limits than 2205 (tolerates dilute HCl up to 30 °C).

2507 vs 2205 corrosion comparison: A Saudi desalination plant tested both alloys—2205 tubes showed pitting after 5 años, mientras2507 seawater corrosion rate (≤0.005 mm/year) kept 2507 tubes operational for 15+ años.

3. High-Temperature & Low-Temperature Properties

2507 performs well across a wide temperature range, though it’s optimized for moderate heat and cold environments.

High-Temperature Traits

• Fortaleza & Oxidación: It maintains 2507 high-temperature strength arriba a 300 °C, con 2507 resistencia a la oxidación hasta 300 °C (suitable for warm chemical processes like acid evaporation). El 2507 continuous service temperature es 300 °C—beyond this, avoid prolonged exposure to prevent sigma phase formation.
• Creep Resistance: 2507 creep rupture data shows it can last 10,000+ hours at 250 °C under 150 MPa stress, making it ideal for high-pressure heat exchanger tubes.

Low-Temperature Traits

• Toughness: It has excellent 2507 low-temperature toughness, con 2507 impact energy at -50 °C of ≥45 J (no brittle fracture). Es 2507 cryogenic ductility also makes it suitable for Arctic offshore projects (p.ej., subsea pipelines in -40 °C conditions).

Un estudio de caso: Estados Unidos. geothermal plant used2507 heat exchanger tubes (operando en 280 °C). Después 8 años, no corrosion or creep deformation occurred—unlike the previous 2205 tubes that failed every 3 años.

4. Tratamiento térmico & Microstructure Balance

Proper heat treatment is critical to maintaining 2507’s 50-50 ferrite-austenite balance and avoiding harmful phases like sigma, chi, or alpha-prime.

Procesos esenciales de tratamiento térmico

• Recocido de solución: Calentar para 1025–1125 °C, mantener durante 30 a 60 minutos, then perform a 2507 rapid water quench (critical to prevent phase formation). This step restores the balanced microstructure and dissolves unwanted carbides.
• Trabajo en caliente: Usar 1150–1000 °C como el 2507 hot working range para forjar o laminar. This keeps the material ductile and preserves the ferrite-austenite balance.
• Alivio del estrés residual: Heat to 400–450 °C to reduce stresses from welding or forming. Avoid 475 °C (el 2507 embrittlement at 475 °C temperatura) to prevent alpha-prime embrittlement.

Control de microestructura

• Ferrite Content: Maintain 2507 ferrite content 35–55 % (tested via magnetic methods) to ensure strength and corrosion resistance.
• Phase Prevention: Avoid heating to 500–800 °C for long periods—2507 sigma phase formation kinetics y 2507 chi phase precipitation accelerate in this range, making the material brittle.

5. Soldadura, Fabricación & Directrices de mecanizado

Soldadura 2507 requires precise heat control to preserve its microstructure, but it’s workable with the right techniques and consumables.

Consejos de soldadura

• Consumables: Usar 2507 welding consumables 2509 / ER2594 (for TIG/MIG welding)—these match 2507’s composition and maintain the ferrite-austenite balance in the weld.
• Heat Input & Interpass Temperature: Strictly control 2507 heat input 0.5–1.5 kJ/mm (lower than 2205’s 0.5–2.5 kJ/mm) and keep 2507 interpass temperature 100 °C max (prevents sigma phase).
• Root Gas Purge: Usar 2507 root gas purge 99.99 % N₂ + 5 % H₂ to ensure full austenite formation in the weld root. Después de soldar, perform 2507 post-weld cleaning passivation (pickling with nitric acid) to remove scale and restore corrosion resistance.

Mecanizado & formando

• Velocidades & Feeds: 2507 machining speeds and feeds should be 15–20% lower than 2205. Usar 2507 tool life with coated carbide (TiAlN or diamond coatings work best—they resist wear from the alloy’s high strength).
• Formability: 2507 formability limits are moderate—cold bending is possible for thin sections, but avoid excessive strain (anneal after heavy forming to restore toughness). Usar 2507 distortion control techniques (p.ej., sujeción durante la soldadura, slow cooling) para mantener las piezas fieles al tamaño.

6. Formularios de productos, Tallas & Cadena de suministro

2507 is available in a wide range of forms to fit nearly any high-corrosion, high-strength project.

Formularios de productos comunes

• Platos & Hojas: 2507 super-duplex plate thickness chart ranges from 3 mm a 200 milímetros; 2507 sheet gauge sizes (16 gauge to 1/2 pulgada) are ideal for chemical vessel liners.
• Tubería & tubos: 2507 seamless pipe ASTM A790 (for high-pressure offshore flowlines) y 2507 welded pipe ASTM A928 (for low-pressure desalination lines).
• Verja & Guarniciones: 2507 round bar stock (10 mm a 300 mm de diámetro), 2507 angle iron sizes (20×20 milímetros a 100×100 milímetros), y 2507 threaded rod grades (Calificación 1 for general use, Calificación 2 for high-stress applications).
• Formularios especiales: 2507 coil slit widths (10 mm a 1250 milímetros), 2507 hollow bar suppliers (for lightweight parts), 2507 custom forgings (p.ej., cuerpos de válvulas), y 2507 clad plate suppliers (for cost-effective large structures like FGD towers).

Consejos para la cadena de suministro

Work with global suppliers who stock2507 seamless pipe ASTM A790 and hold NACE MR0175 certification—these ensure compliance for sour service. For urgent offshore projects, prioritize suppliers with local inventory of common sizes to reduce lead times.

7. Aplicaciones industriales & Estudios de caso

2507’s unbeatable strength and corrosion resistance make it a top choice for industries facing extreme conditions. Estos son los casos de uso clave:

• Offshore & Marina: 2507 offshore flowlines, 2507 subsea pipelines, y 2507 chemical injection lines (resist seawater, H₂S, and high pressure).
• Water Treatment: 2507 desalination high-pressure piping (manijas 80+ bar pressure and high chlorides).
• Power & Industrial: 2507 FGD absorber towers (remove sulfur from power plant exhausts) y 2507 heat exchanger tubes (for acid and geothermal applications).
• Pulp & Paper: 2507 pulp & paper digesters (resist chlorine-based bleaches and high temperatures).

Un ejemplo real: A Brazilian oil company replaced 2205 con 2507 for subsea wellheads—2507 sulfide stress cracking resistance eliminated wellhead failures, cutting maintenance costs by 90% and extending service life from 7 a 20 años.

La perspectiva de la tecnología Yigu

En Yigu Tecnología, recomendamos 2507 for clients needing extreme corrosion resistance + alta resistencia. Nosotros obtenemos2507 ASTM A240 platos y2507 seamless pipe ASTM A790 de molinos certificados, ensuring PREN 41–45 and ferrite content 35–55%. For offshore/sour service clients, we provide NACE MR0175 testing and welding support (usando2509/ER2594 consumables). Mientras 2507 costs more than 2205, its 2x longer lifespan and lower maintenance make it cost-effective for the harshest projects.

Preguntas frecuentes

1. When should I choose 2507 encima 2205?
   Elegir 2507 if your project involves high chlorides (>10,000 ppm), sour service (H₂S), or high pressure (>300 bar). Es PREN 41–45 y sulfide stress cracking resistance outperform 2205. Usar 2205 for milder conditions (p.ej., low-pressure seawater) to save cost.
2. Can 2507 be used at temperatures above 300 °C?
   Avoid prolonged use above 300 °C (its continuous service temperature). At 300–500 °C, 2507 sigma phase formation y alpha-prime embrittlement occur, reducing toughness. Para 300 °C+ applications, choose 347H (high-temperature strength) or 904L (resistencia a la corrosión).
3. What’s critical for welding 2507?
   Three key steps: Usar 2507 welding consumables 2509/ER2594, control heat input 0.5–1.5 kJ/mm y interpass temperature 100 °C max, and purge the root with 99.99 % N₂ + 5 % H₂. Post-weld passivation is also required to restore corrosion resistance.