Type 2507 (UNS S32750)


2507 stainless steel was designed for demanding applications which require exceptional strength and corrosion resistance, such as chemical process, petrochemical, and seawater equipment. As a duplex (ferritic-austenitic) stainless steel, 2507 combines the most desirable characteristics of both ferritic and austenitic steels.

The duplex microstructure gives this grade high strength, excellent resistance to chloride stress corrosion cracking, high thermal conductivity, and a low coefficient of thermal expansion. In addition, 2507’s high chromium, molybdenum, and nitrogen levels provide excellent resistance to pitting, crevice, and general corrosion that is similar to the 6% Mo super austenitic stainless steels.

Chemical Composition

Chemical Composition (wt%) limits as specified in ASTM A276 and ASME SA276*

Carbon 0.030 Silicon 0.80
Chromium 24.0-26.0 Copper 0.50
Nickel 6.0-8.0 Nitrogen 0.24-0.32
Molybdenum 3.0-5.0 Phosphorus 0.035
Manganese 1.20 Sulfur 0.020

*Maximum, unless range is indicated

Physical Properties

Physical properties for Super Duplex 2507 Stainless Steel

Density, lb/in3 0.280
Modulus of Elasticity, psi 29.0x 106
Coefficient of Thermal Expansion, 68-212˚F, /˚F 7.5 x 10-6
Thermal Conductivity, Btu/ft hr ˚F 8
Specific Heat, Btu/lb ˚F 0.12
Electrical Resistivity, Microhm-in 31.5

Mechanical Properties

Mechanical property requirements for annealed, hot finished product as specified in ASTM A276 and ASME SA276

Yield Strength, min. (ksi) 80
Tensile Strength, min. (ksi) 116
Elongation, min. (%) 15
Hardness, max. (HBW) 310


Typical standards for Super Duplex 2507 Stainless Steel