GENERAL PROPERTIES

Duplex 2507 (UNS S32750) is a super duplex stainless steel with 25% chromium, 4% molybdenum, and 7% nickel designed for demanding applications which require exceptional strength and corrosion resistance, such as chemical process, petrochemical, and seawater equipment. The steel has excellent resistance to chloride stress corrosion cracking, high thermal conductivity, and a low coefficient of thermal expansion. The high chromium, molybdenum, and nickel levels provide excellent resistance to pitting, crevice, and general corrosion.

Applications

• Oil and gas industry equipment
• Offshore platforms, heat exchangers, process and service water systems, fire-fighting systems, injection and ballast water systems
• Chemical process industries, heat exchangers, vessels, and piping
• Desalination plants, high pressure RO-plant and seawater piping
• Mechanical and structural components, high strength, corrosion-resistant parts
• Power industry FGD systems, utility and industrial scrubber systems, absorber towers, ducting, and piping

Standards
ASTM/ASME ………. A240 – UNS S32750
EURONORM………… 1.4410 – X2 Cr Ni MoN 25.7.4
AFNOR……………….. Z3 CN 25.06 Az

CORROSION RESISTANCE

General Corrosion

• high chromium and molybdenum content of 2507 makes it extremely resistant to uniform corrosion by organic acids like formic and acetic acid.
• provides excellent resistance to inorganic acids, especially those containing chlorides.
• can be used in dilute hydrochloric acid.
• Pitting need not be a risk in the zone below the borderline in this figure, but crevices must be avoided.

Intergranural Corrosion

• Low carbon content greatly lowers the risk of carbide precipitation at the grain boundaries during heat treatment.
• Is highly resistant to carbide-related intergranular corrosion.

Stress Corrosion Cracking

• Duplex structure of 2507 provides excellent resistance to chloride stress corrosion cracking (SCC).
• Superior to 2205 in corrosion resistance and strength.
• 2507 is especially useful in offshore oil and gas applications and in wells with either naturally high brine levels or where brine has been injected to enhance recovery.

Pitting Corrosion

• Different testing methods can be used to establish the pitting resistance of steels in chloride-containing solutions.

Crevice Corrosion

• Highly resistant to crevice corrosion.

Chemical Properties

Typical values (Weight %)

Mechanical Properties

Physical Properties