Hangbo Alloy Group supplies a variety of 2507 super duplex stainless steel products, including round bars, plates, strips, seamless tubes, forgings, and wires. Below is a comprehensive description of 2507 super duplex stainless steel.
1. Introduction to 2507 Super Duplex Stainless Steel
Description: 2507 (UNS S32750) is a high-performance super austenitic-ferritic duplex stainless steel, mainly composed of chromium, nickel, molybdenum, and nitrogen. It features a balanced dual-phase structure (~50% austenite + ~50% ferrite), which integrates the excellent corrosion resistance of super austenitic stainless steel and the ultra-high strength of ferritic stainless steel. It exhibits extreme resistance to chloride stress corrosion cracking (SCC) and pitting/crevice corrosion (PRE ≥ 40), outstanding mechanical properties in the temperature range of -50°C to 300°C, and ultra-high tensile strength (≥800 MPa). These characteristics make it ideal for ultra-harsh environments with high-concentration corrosive media (especially chloride-containing) and extreme structural load requirements.
International Equivalents:
USA: S32750, ASTM 2507
CHINA: 022Cr25Ni7Mo4N (per GB/T 20878 standard)
Europe: EN 1.4410, DIN X2CrNiMoN25-7-4
2. Standards for 2507 Super Duplex Stainless Steel
Plates: ASTM A240/A240M (Grade 2507), GB/T 4237, EN 10088-2
Round Bars: ASTM A276 (Grade 2507), GB/T 1220, EN 10088-3
Seamless Tubes: ASTM A789/A790 (Grade 2507), GB/T 14976, EN 10216-5
Forgings: ASTM A182/A182M (Grade 2507), GB/T 1221, EN 10222-5
3. Chemical Composition of 2507 Super Duplex Stainless Steel
| Element | Content (%) |
|---|---|
| Carbon (C) | ≤ 0.03 |
| Chromium (Cr) | 24.0-26.0 |
| Nickel (Ni) | 6.0-8.0 |
| Silicon (Si) | ≤ 0.80 |
| Manganese (Mn) | ≤ 1.20 |
| Phosphorus (P) | ≤ 0.035 |
| Sulfur (S) | ≤ 0.02 |
| Iron (Fe) | Balance |
| Molybdenum (Mo) | 3.0-5.0 |
| Nitrogen (N) | 0.24-0.32 |
| Copper(Cu) | ≤ 0.50 |
4. Physical Properties of 2507 Super Duplex Stainless Steel
| Property | Value |
|---|---|
| Density | 8.03 g/cm³ |
| Melting Range | 1300 - 1390 °C |
5. Material Characteristics of 2507 Super Duplex Stainless Steel
Extreme Chloride Corrosion Resistance: Far superior to 2205/316L in resistance to chloride stress corrosion cracking, pitting, and crevice corrosion (suitable for high-concentration brine, high-temperature seawater, and strong acidic chloride media).
Ultra-High Mechanical Strength: Tensile strength (≥800 MPa) and yield strength (≥550 MPa) are 2-3 times higher than 304/316 stainless steel; further reduces component thickness and weight, cutting long-term costs.
Balanced Dual-Phase Structure: ~50% austenite + ~50% ferrite ensures excellent low-temperature toughness (no brittle fracture at -50°C) and fatigue resistance, avoiding the brittleness of single-phase ferritic steels.
Controllable Weldability: Compatible with standard welding methods (TIG, MIG); strict heat input control (0.5-1.5 kJ/mm) maintains post-weld dual-phase balance and corrosion resistance; self-fusion welding requires post-weld annealing.
Medium-Temperature Stability: Maintains stable performance at temperatures up to 300°C; avoids phase transformation or toughness degradation under long-term medium-temperature service.
6. Applications of 2507 Super Duplex Stainless Steel
Deep-Sea Oil & Gas Industry: Used in subsea wellhead equipment, high-pressure pipelines for offshore platforms, and acidizing fracturing tools; withstands high-pressure, high-salinity, and H₂S-containing media.
High-Concentration Seawater Desalination: Applied to reverse osmosis (RO) high-pressure membrane housings and brine discharge pipelines; resists extreme chloride erosion.
Strong Corrosion Chemical Industry: Used in high-concentration hydrochloric acid reactors, sulfuric acid recovery systems, and chemical liquid cargo ship pipelines; avoids pitting/crevice corrosion in harsh acidic environments.
Environmental Engineering: Employed in flue gas desulfurization (FGD) systems and high-concentration sewage treatment equipment; resists corrosion from acidic flue gas and toxic sludge.
Extreme Marine Engineering: Used in deep-sea ship hull components, underwater propeller shafts, and offshore wind power platform structures; combines ultra-high strength and long-term seawater corrosion resistance.
