Detailed Product Description

Super Duplex Stainless Steel Pipe – ASTM A790 UNS S32750 / S32760 – Seamless & Welded – High Strength Corrosion Resistant Pipe

Super duplex stainless steel pipe is a high-performance ferritic-austenitic stainless steel with approximately 25% chromium, 7% nickel, 4% molybdenum, and nitrogen. The balanced austenite-ferrite microstructure (typically 40-60% ferrite) delivers exceptional strength—approximately 2.5 times stronger than 316L stainless steel—combined with outstanding corrosion resistance. With a Pitting Resistance Equivalent Number (PREN) of 42 or higher, super duplex pipes offer superior resistance to pitting, crevice corrosion, and chloride stress corrosion cracking. Manufactured to ASTM A790 / ASME SA790 standards, these pipes are widely used in offshore oil and gas, chemical processing, marine engineering, and desalination plants.

Product Description

Specifications

Super Duplex Stainless Steel Pipe – ASTM A790

Product Parameters

Chemical Composition

UNS S32750 (Super Duplex 2507 / SAF 2507®)

UNS S32760 (Zeron 100® / 1.4501)

Mechanical Properties

UNS S32750 (Solution Annealed)

UNS S32760 (Solution Annealed)

Physical Properties

Main Characteristics

1. High Mechanical Strength
Super duplex stainless steel offers approximately 2.5 times the yield strength of 316L stainless steel (550 MPa vs. 220 MPa). This allows for thinner wall sections at the same design pressure, reducing weight and overall system cost.

2. Exceptional Corrosion Resistance
With a PREN (Pitting Resistance Equivalent Number) of 42 or higher, super duplex pipes provide outstanding resistance to pitting, crevice corrosion, and chloride stress corrosion cracking (SCC). The material is resistant to sulfuric acid, acetic acid, and seawater.

3. Stress Corrosion Cracking Resistance
Super duplex grades resist chloride-induced stress corrosion cracking up to 200°C (392°F) under NACE TM0177 testing, making them ideal for offshore and marine environments.

4. Balanced Microstructure
The austenitic-ferritic structure (approximately 50:50) combines the desirable characteristics of both ferritic and super-austenitic steels, providing high strength, excellent toughness, and good weldability.

5. Good Weldability
Super duplex pipes can be welded using standard methods (TIG, MIG, SMAW) with AWS A5.9 ER2594 filler, and no post-weld heat treatment is required for most applications.

6. Wide Temperature Range
Suitable for service temperatures up to 315°C (600°F). Not recommended for long-term exposure above 570°F due to risk of reduced toughness.

7. Solution Annealed & Water Quenched
All pipes undergo solution annealing at 1025-1125°C followed by rapid water quenching to achieve the target phase balance and optimal corrosion resistance.

8. ASTM A923 Testing
Intermetallic phase testing per ASTM A923 (Method A, B, or C) is mandatory to detect detrimental sigma and chi phases that can degrade toughness and corrosion resistance.

Corrosion Resistance

Super duplex stainless steel provides exceptional resistance to:

• Pitting and crevice corrosion (PREN ≥ 42)

• Chloride stress corrosion cracking (SCC)

• Erosion corrosion and corrosion fatigue

• General corrosion in acids

• Seawater and high-salinity environments

• Sulfuric acid and acetic acid

Application Field

Super duplex stainless steel pipes are widely used in demanding environments requiring high strength and exceptional corrosion resistance.

1. Offshore oil and gas – subsea pipelines, flowlines, risers, manifolds

2. Marine engineering – seawater cooling systems, shipbuilding, hydraulic and instrumentation systems

3. Chemical and petrochemical processing – heat exchangers, process piping, reactors

4. Desalination plants – reverse osmosis and thermal process piping

5. Pulp and paper industry – digesters, bleach plants

6. Power generation – condenser tubing, cooling water systems

7. Water treatment – wastewater and brackish water systems

Our Service

Why Choosing TOBO Metal Industrial:

• Sufficient Forging, Heating, and Machining Equipment

• In-house Inspection Instruments for Quality Control

• Competitive Price & High Quality Assurance

• Fast, Effective and Efficient Services

• Direct Supplier of Danieli Metallurgical Equipment

• Experienced Professionals in Communication

• Complete Traceability with Mill Test Reports (EN 10204 3.1 / 3.2)

Our Company

1. We are one of the Professional Manufacturers and Exporters of Pipeline Products in China. Our company was established in 1998, the plant covers 550,000 square meters with a construction area of 68,000 square meters, employing 260 workers and 45 technicians.

2. We have five branch factories which can supply the best quality pipes, tubes, fittings, flanges, and related accessories. Now, we own a number of advanced pipe production equipments, including metal processing, forging, machining, cold forming, and hot extrusion facilities. Annual production capacity exceeds 60,000 tons of pipe and pipe fittings. Our company maintains various detection devices, such as non-destructive testing, chemical analysis, metallographic examination, and physical experiments. Our main products include seamless and welded pipes, fittings, forged socket welding fittings, threaded fittings, and flanges. Materials cover stainless steel, duplex stainless steel, super duplex stainless steel, alloy steel, and nickel alloys.

3. In addition, we are authorized by more than 120 top-class mills from South Korea, Japan, and China like JFE, SUMITOMO, POSCO, BAOSTEEL, TISCO, LISCO, TPCO, HENGYANG VALIN, and so on.

Packing & Delivery

1. Packing Details: Regular shipping packaging (wooden cases, steel frames, or bundles) or depends on customer's requirement

2. Delivery Details: 7-15 days after the purchase order

FAQ

Q: Are you a trading company or manufacturer?
A: We are a factory with direct production capabilities.

Q: How long is your delivery time?
A: Generally it is 5-10 days if the goods are in stock. For custom orders, it is 15-20 days depending on quantity and specifications.

Q: Do you provide samples? Is it free or extra?
A: Yes, we could offer samples free of charge, but the customer pays the freight cost.

Q: What are your terms of payment?
A: Payment ≤ 1000 USD, 100% in advance. Payment ≥ 1000 USD, 50% T/T in advance, balance before shipment.

Q: What is the difference between UNS S32750 and UNS S32760?
A: Both are super duplex grades with similar properties. UNS S32760 (Zeron 100) contains additional tungsten and copper, offering slightly enhanced corrosion resistance in aggressive chloride environments.

Q: What is the PREN value of super duplex stainless steel?
A: The PREN (Pitting Resistance Equivalent Number) is 42 or higher for super duplex grades, compared to approximately 36 for standard duplex 2205