2507 duplex stainless steel

2507 Duplex stainless steel is a ferritic-austenitic (duplex) stainless steel with excellent resistance to point corrosion, crevice corrosion and uniform corrosion. Its composition is 25Cr-7Ni-4Mo-0.27N, in accordance with EURONORM standard 1.4410-X2 CrNi MoN 25.7.4.

2507 duplex stainless steel combines many of the most 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 biphase microstructure ensures that the steel has a high resistance to stress corrosion cracking and a high mechanical strength.

2507 duplex stainless steel is widely used in the 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 equipment in the high pressure pipe, seawater pipe); Mechanical and structural components that require both high strength and high corrosion resistance; Fuel (waste) gas purification equipment. Main composition: 25Cr-7Ni-4Mo-0.27N.

National standards include 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, etc.

SAF 2507 duplex stainless steel has a high chromium and molybdenum content, so that it has a strong overall corrosion resistance to organic acids such as formic acid, acetic acid and so on. It also has strong corrosion resistance to inorganic acids, especially those containing chlorides. Compared with 904L, SAF 2507 has stronger corrosion resistance to diluted sulfuric acid mixed with chloride ions. 904L is an austenitic alloy designed to resist pure sulfuric acid corrosion.

Grade 316L is not intended for use in hydrochloric acid environments, where it may be subject to local or overall corrosion. SAF 2507 can be used in diluted hydrochloric acid environment, with strong resistance to spot damage and crack corrosion.

The low carbon content of SAF 2507 duplex stainless steel greatly reduces the risk of carbide precipitation in the intergranular during heat treatment, and as a result, this alloy has a strong resistance to carbde-related intergranular corrosion.

The SAF 2507 duplex stainless steel structure gives it a strong resistance 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 isocorrosion curve in hydrochloric acid is 0.1mm /year.