2507 Same grade from different mill standard
S32750 00Cr25Ni7Mo4N 022Cr25Ni7Mo4N 1.4410
C：≤0.03 ，Si ：≤0.8 Mn：≤2.0 ，Cr：24.0～26.0 ，Ni：8.0～8.0， S ：≤0.02 ，P ：≤0.035 Mo: 3.0～5.0, Cu: < 0.5 , N: ≤0.24～0.32
2507 Chemical component ASTM A240
2507 mechanical property ASTM A240
Tensile strength : > 795 Mpa
Yield Strength : >550 Mpa
Elongation (%): > 15%
Hardness: < HV310
Simple description about duplex/super duplex stainless steel 2205/ 2507
Duplex Stainless Steel (DSS) refers to approximately 50% of ferrite and austenite and generally contains less than 30% of stainless steel. In the case of lower C content, the Cr content is 18% to 28%, and the Ni content is 3% to 10%. Some steels also contain alloying elements such as Mo, Cu, Nb, Ti, and N.
This type of steel combines the characteristics of austenitic and ferritic stainless steels. Compared with ferrite, it has higher plasticity and toughness, no brittleness at room temperature, significantly improved resistance to intergranular corrosion and welding performance, and at the same time retains iron. The 475°C brittleness and high thermal conductivity of the ferritic stainless steel make it superplastic. Compared with austenitic stainless steels, they have high strength and resistance to intergranular corrosion and chloride stress corrosion resistance. Duplex stainless steel has excellent pitting corrosion resistance and is also a nickel-saving stainless steel.
Duplex stainless steel classification
The first type is a low-alloy type, which stands for UNS S32304 (23Cr-4Ni-0.1N). The steel does not contain molybdenum and its PREN value is 24-25. It can be used instead of AISI304 or 316 in terms of stress corrosion resistance.
The second type of alloy is a type of alloy, represented by UNS S31803 (22Cr-5Ni-3Mo-0.15N) with a PREN value of 32-33, and its corrosion resistance is between AISI 316L and 6% Mo+N austenitic stainless steel. between.
The third category is a high alloy type, generally containing 25% Cr, also containing molybdenum and nitrogen, and some also contain copper and tungsten, standard grade UNSS32550 (25Cr-6Ni-3Mo-2Cu-0.2N), PREN value is 38-39 The corrosion resistance of this type of steel is higher than that of 22% Cr duplex stainless steel.
The fourth type is a super duplex stainless steel type, containing high molybdenum and nitrogen, standard grade UNS S32750 (25Cr-7Ni-3.7Mo-0.3N), some also containing tungsten and copper, PREN value greater than 40, can be applied to harsh Medium conditions, with good corrosion and mechanical properties, comparable to super austenitic stainless steels.