2507 is a ferritic-austenitic (duplex) stainless steel

2507 is a ferritic-austenitic (duplex) stainless steel

2507 is a ferritic-austenitic (duplex) stainless steel, which combines many of the beneficial properties of ferritic steel and austenitic steel, because the steel has a high content of chromium and molybdenum, so it has excellent resistance to spot corrosion, crevice corrosion and uniform corrosion. The bidirectional microstructure ensures that the steel has a high resistance to stress corrosion cracking and a high mechanical strength.

2507 is a ferritic-austenitic (duplex) stainless steel, which combines many of the beneficial properties of ferritic steel and austenitic steel, because the steel has a high content of chromium and molybdenum, so it has excellent resistance to spot corrosion, crevice corrosion and uniform corrosion. The bidirectional microstructure ensures that the steel has a high resistance to stress corrosion cracking and a high mechanical strength.
2507 stainless steel is used in oil and gas industry; Offshore oil platform (heat exchanger tube, water treatment and water supply system, fire fighting system, sprinkler system, water stabilization system; Petrochemical equipment; Desalination (desalination) equipment (and high-pressure pipes in the equipment, seawater pipes); Mechanical and structural components that require both high strength and high corrosion resistance; Fuel (waste) gas purification equipment.
National standards:
ASTM/ASME:A240 - UNS S32750
EURONORM: 1.4410-X2 Cr Ni MoN 25-7-4
AFNOR:Z3 CN 25.06 Az
DIN/EN: 1.4410, ASME SA-240
CHINA:022Cr25Ni7Mo4N

Corrosion resistance
1. General corrosion
The high chromium and molybdenum content of SAF 2507 makes it have strong resistance to organic acids such as formic acid and acetic acid. SAF2507 alloy also has strong corrosion resistance to inorganic acids, especially those containing chlorides.
SAF2507 is more resistant to diluted sulfuric acid mixed with chloride ions than 904L, an austenitic alloy specifically designed to resist pure sulfuric acid.
Grade 316L is not intended for use in hydrochloric acid environments, where it may be subject to local or overall corrosion. SAF2507 can be used in diluted hydrochloric acid environment, with strong resistance to spot damage and crack corrosion.
2. Intergranular corrosion
The low carbon content of nSAF 2507 greatly reduces the risk of carbide precipitation in the intergranular during heat treatment, and as a result, the alloy is highly resistant to carbde-related intergranular corrosion.
3. Stress corrosion cracking
The duplex structure of SAF 2507 makes it highly resistant to stress corrosion cracking. Due to its higher alloy content,SAF 2507 has better corrosion resistance and strength than 2205.
Cracks are almost inevitable in construction and other aspects, which makes stainless steel more susceptible to corrosion in chloride environments. SAF 2507 has a strong resistance to crack corrosion. The isocorrosion curve of SAF 2507 in sulfuric acid containing 2000ppm chloride ions is 0.1mm /year; The isoetch curve in hydrochloric acid is 0.1mm /year.
Mechanical properties :SAF 2507 has high compressive strength, impact strength, low coefficient of thermal expansion and high thermal conductivity. These characteristics apply to many structural and mechanical components. SAF 2507 has a very high impact strength and should not be exposed to temperatures higher than 570°F for long periods of time, which may reduce its toughness. Tensile strength: σb≥730Mpa; Elongation: δ≥20%
Matching welding materials: ER2594 wire, E2594 electrode
Applications: pulp and paper industry, seawater desalination, flue gas purification, heat exchanger, chemical liquid cargo ship piping system, seawater system, etc.