2507 (UNS S32750) belongs to the third-generation super duplex stainless steel. After solution annealing, the microstructure consists of approximately 50% austenite and 50% ferrite. It is formulated with high chromium, high molybdenum, and high nitrogen alloys, offering superior corrosion resistance and strength compared to standard duplex 2205. It is specifically designed for extreme corrosive conditions such as high chloride, high temperature, and presence of hydrogen sulfide; commercial grade: SAF 2507.

Operating temperature range: -50℃ to 300℃. Long-term use is strictly prohibited above 300℃. At high temperatures, σ intermetallic phase is prone to precipitate, significantly reducing toughness and corrosion resistance.

Chemical composition of each grade:

Performance data of various grades of metal (for reference only) :

Physical properties of each grade:

Material properties

Extreme resistance to local corrosion (core advantage)

Resistance to pitting/corrosion of crevices: The critical pitting temperature (CPT) is ≥ 75℃ for 2205, while it is only around 50℃ for 2205; It is difficult for high-temperature stagnant seawater and high-salt wastewater to penetrate;

Resistance to chloride stress corrosion (SCC): In high-chloride and high-temperature pressure-bearing conditions, there is almost no cracking risk, far exceeding 316L;

Resistance to sulfide corrosion: Meets NACE oil and gas standards, suitable for crude oil containing H₂S and formation water;

Uniform corrosion: The annual corrosion rate of weak acid, seawater, and brine is extremely low.

Ultra-high strength and lightweight

The yield strength is 2.7 times that of 316L stainless steel. Equivalently sized pressure-bearing equipment can significantly reduce the wall thickness and lower the equipment's weight.

Application fields

Marine and deep-sea engineering: submarine pipelines, offshore oil and gas platforms, high-pressure equipment for seawater desalination, seawater pumps and valves, submarine gathering and transportation manifolds;

Petroleum and natural gas: sulfur-containing oil and gas pressure vessels, downhole pipelines, NACE acidic medium equipment;

Environmental desulfurization and chemical industry: high-concentration chloride salt wastewater, high-temperature flue gas desulfurization devices, concentrated acid and alkali reaction vessels;

Chemical and pharmaceutical: high-purity reagent storage tanks, chloride compound reactors, fine chemical corrosion equipment;

Energy and power: nuclear power plant seawater circulation system, power plant high-temperature seawater coolers;

Others: coastal high-pressure water treatment, paper bleaching high-temperature high-chlorine equipment.