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Our products conform to GB, AISI, ASTM, DIN, EN, JIS standard for stainlesss steel coil, sheet and plate.
┃ Material
S32750, 1.4410, X2CrNiMoN2574, 022Cr25Ni7Mo4N
S32760, 1.4501, X2CrNiMoCuWN2574, 022Cr25Ni7Mo4WCuN
┃ Overview
2507 super duplex stainless steel contains 25% chromium, 4% molybdenum, and 7% nickel are 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.
2507 SDSS like S32750 and S32760, is a mixed microstructure of austenite and ferrite (50/50) which has improved strength over ferritic and austenitic steel grades. The main difference is that Super Duplex has a higher molybdenum and chromium content which gives the material greater corrosion resistance than standard duplex grades.
┃ Characteristics
◇ Excellent resistance to stress corrosion cracking (SCC) in chloride-bearing environments
◇ Excellent resistance to pitting and crevice corrosion
◇ High resistance to general corrosion
◇ Very high mechanical strength
◇ Physical properties that offer design advantages
◇ High resistance to erosion corrosion and corrosion fatigue
◇ Good weldability
┃ Application
2507 SDSS are widely used in following industries
Oil-gas
Chemical processing
Subsea control line
Heat exchangers
Offshore plateforms
Fire-fighting system
Injection & ballast water systems
Vessels
Desalination plants
Energy industry FGD system, industrial scrubbing system, absorption tower
┃ Chemical composition (wt% as per ASTM A789 / A790)
Material |
C |
Si |
Mn |
P |
S |
Cr |
S32750 |
≤0.03 |
≤0.80 |
≤1.20 |
≤0.030 |
≤0.020 |
24.0~26.0 |
S32760 |
≤0.03 |
≤1.0 |
≤1.0 |
≤0.030 |
≤0.020 |
24.0~26.0 |
Material |
Ni |
Mo |
N |
Cu |
W |
|
S32750 |
6.0~8.0 |
3.0~5.0 |
0.24~0.32 |
≤0.50 |
|
|
S32760 |
6.0~8.0 |
3.0~4.0 |
0.20~0.30 |
0.50~1.00 |
0.50~1.00 |
|
S32750: PREN ≥ 41, S32760: PREN ≥ 40.
┃ Corrosion resistance
Pitting corrosion resistance
Pitting and crevice corrosion resistance is generally a function of an alloy’s chromium, molybdenum and nitrogen contents. Calculated indexes have been devised to roughly predict and rank alloys for pitting resistance based on these elements (in weight-%). The higher the index the higher the predicted pitting corrosion resistance.
Stress corrosion cracking resistance
To achieve resistance to stress corrosion cracking in stainless steels, the nickel content must either be low as in the ferritic group of steels, or very high making them correctly nickel base alloys. The ferritic stainless steels are nearly immune to SCC, but are difficult to fabricate and are subject to brittle behavior at low temperatures. Nickel, and high nickel alloys also possess excellent SCC resistance but are costly due to their high nickel content. The low nickel austenitic stainless steels (304, 316, 317) have poor SCC resistance compared to ferritic stainless and high nickel alloys.
┃ Mechanical property
Material |
Tensile strength ksi (MPa) |
Yield strength ksi (MPa) |
Elongation in 2” % min. |
Hardness HBW /HV max. |
S32750 |
116 (800) |
80 (550) |
15 |
300 / 300 |
S32760 |
109 (750) |
80 (550) |
25 |
310 / 310 |
┃ Heat treatment
S32750: 1880-2060 (1025-1125), rapid cooling in water or air.
S32760: 1960-2085 (1070-1140), rapid cooling in water or air.
┃ Available Process
(1) Hot formed, solution annealed, descaled
(2) Cold worked and bright annealed
(3) Cold worked, annealed and descaled
(4) Cold worked, polished (MP, EP etc.)
(5) Cold worked, bright annealed, polished (MP, EP etc.)
┃ Common Tests
Chemical composition
Tension
Hardness
Flaring
Flange
Flattening
Micro structure
Hydrostatic
NDT
Intergranular Corrosion
Surface condition
Shape and dimension
Positive Material Identification