Super Duplex 2507 S32750 Stainless Steel Seamless Pipe

2507 Duplex Stainless Steel Seamless Pipe: An Overview

2507 duplex stainless steel seamless pipe is a premium ferritic-austenitic duplex alloy, renowned for its exceptional balance of corrosion resistance, mechanical strength, and durability. Below is a comprehensive introduction covering its parameters, performance, features, similar grades, standards, packaging, and applications:

Parameters

• Chemical Composition (Typical, wt%):

  • Carbon (C) ≤ 0.03

  • Manganese (Mn) ≤ 2.00

  • Silicon (Si) ≤ 1.00

  • Chromium (Cr): 21.0 – 24.0

  • Nickel (Ni): 4.5 – 6.5

  • Molybdenum (Mo): 2.5 – 3.5

  • Nitrogen (N): 0.14 – 0.20

  • Phosphorus (P) ≤ 0.035

  • Sulfur (S) ≤ 0.020

• Mechanical Properties:

  • Tensile Strength (σb): ≥ 795 MPa

  • Yield Strength (σ0.2): ≥ 550 MPa

  • Elongation (δ): ≥ 15%

  • Hardness: ≤ 310 HB (Brinell)

• Physical Properties:

  • Density: 8.03 g/cm³

  • Melting Point: 1300 – 1390°C

  • Magnetic Property: Non-magnetic

  • Thermal Conductivity: ~15 W/(m·K) at 20°C

Performance

• Corrosion Resistance:

  • Excellent resistance to pitting, crevice corrosion, and general corrosion in chloride-rich environments (e.g., seawater, brines).

  • High tolerance to organic acids (formic, acetic) and dilute inorganic acids (sulfuric, hydrochloric) with chloride ions.

  • Pitting Resistance Equivalent Number (PREN) ≥ 40, outperforming many austenitic stainless steels (e.g., 316L with PREN ~32).

• Mechanical Performance:

  • Combines high strength (twice that of 316L) and good toughness, maintaining ductility even at low temperatures.

  • Resistant to stress corrosion cracking (SCC), a critical advantage over austenitic grades in chloride environments.

Key Features

• Duplex Microstructure: Equal proportions of ferritic and austenitic phases, balancing strength (ferrite) and corrosion resistance (austenite).

• Weldability: Compatible with standard welding processes (TIG, MIG); post-weld heat treatment is often unnecessary, ensuring weld integrity.

• Cost-Effectiveness: Higher strength reduces material thickness requirements, lowering overall project costs compared to thicker-walled austenitic pipes.

• Low Magnetic Permeability: Nearly non-magnetic, suitable for applications requiring minimal magnetic interference.

Similar Grades

• UNS S32750

• SAF 2507 (Sandvik designation)

• F53 (ASTM designation for forgings)

• W.Nr. 1.4410 (DIN/EN standard)

• NAS 74N (Nippon Steel designation)

Standards

• ASTM A312 / ASME SA-312: Seamless and welded austenitic stainless steel pipes.

• ASTM A790 / ASME SA-790: Seamless and welded duplex stainless steel pipes.

• ASTM A269: Seamless and welded austenitic stainless steel tubing for general service.

• EN 10216-5: Seamless steel tubes for pressure purposes – Duplex stainless steels.

Packaging

• Ends of pipes are capped with plastic or metal protectors to prevent damage and contamination.

• Pipes are bundled with steel straps, wrapped in waterproof plastic film, and placed on wooden pallets or in seaworthy plywood crates for export.

• Custom packaging (e.g., anti-rust coating, labeled bundles) is available per customer requirements.

Applications

• Marine Engineering: Seawater intake systems, desalination plants, offshore oil/gas pipelines.

• Chemical Processing: Pipes for handling acids, chlorides, and corrosive slurries.

• Oil & Gas Industry: Downhole tubing, wellhead equipment, and subsea pipelines.

• Pulp & Paper: Digester lines, bleach plants, and wastewater treatment systems.

• Construction: Structural pipes in harsh environments (coastal bridges, chemical storage facilities).