Stainless Steel-Duplex 2507

Duplex stainless steels possess high mechanical properties and excellent corrosion resistance, and have been widely applied in various industries such as marine and offshore oil & gas, petrochemicals, pulp and paper, seawater systems, pharmaceuticals, food processing, and chemical fertilizer industries. Common grades include ultra-low carbon duplex stainless steels such as 18Cr-5Ni-3Mo, 22Cr-5Ni-3Mo, and 25Cr-7Ni-4Mo, commonly referred to as 1805, 2205, and 2507, respectively. 1805 is typically used in applications with lower stress and corrosive environments; 2205, due to its high strength, excellent intergranular corrosion resistance, and uniform corrosion resistance, can replace 304L and 316L stainless steels [1]; 2507, in addition to the advantages of 2205, exhibits superior resistance to chloride pitting and crevice corrosion compared to 316L, and has already been used abroad for manufacturing key equipment in urea synthesis processes. This paper will analyze and explore the characteristics of 2507 duplex stainless steel from aspects such as material properties, formability, weldability, and heat treatment performance. Based on the inherent properties of 2507 duplex stainless steel, some requirements for its application in equipment manufacturing and engineering projects will be proposed.
2507 Duplex is highly resistant to uniform corrosion by organic acids such as formic and acetic acid. It is alsohighly resistant to inorganic acids, especially if they contain chlorides. Alloy 2507 is highly resistant to carbide-related intergranular corrosion. Due to the ferritic portion of the duplex structure of the alloy it is very resistant to stress corrosion cracking in warm chloride containing environments. Through additions of chromium, molybdenum and nitrogen localized corrosion such as pitting and crevice attack are improved. Alloy 2507 has excellent localized pitting resistance.