Overview
2507 stainless steel pipe is a super duplex grade for which elements chromium, nickel and molybdenum are the primary alloyants. Chemically speaking, the Duplex 2507 tubing is produced by alloying 25% chromium, 4% molybdenum, along with 7% nickel.
Hence, due to its chemical composition with regards to its highest alloyant content, this grade is also referred to as 25cr Super Duplex Pipe. This particular grade of duplex 2507 stainless steel pipe is famous for its excellent resistance to chloride ion stress related corrosion cracking, which has been attributed to the duplex micro structure of the alloy.
Equivalent Material
| Grade | European EN | China GB | Japanese JIS |
| 2507 | 1.4410 | 00Cr22Ni5Mo3N | SUS2507 |
Features
The higher chromium and molybdenum content of 2507 make it have strong resistance to overall corrosion against organic acids such as formic acid and acetic acid.
2507 stainless steel also have strong corrosion resistance to inorganic acids, especially those containing chlorides.
Compared with 904L, 2507 has stronger corrosion resistance to diluted sulfuric acid mixed with chloride ions.
904L stainless steel pipe is an austenitic alloy pipe specially designed to resist corrosion by pure sulfuric acid.
316L stainless steel pipe can not be used in hydrochloric acid environment, it may suffer local corrosion or overall corrosion.
2507 is used in diluted hydrochloric acid environment and has strong resistance to pitting and crevice corrosion.
The lower carbon content of 2507 greatly reduces the risk of carbide precipitation in the intergranular during heat treatment. Therefore, this alloy has a strong ability to resist intergranular corrosion associated with carbides.
The weldability of duplex 2507 stainless steel pipe is very good.
The required performance of 2507 alloy is that the weld metal and thermally deteriorated parts still maintain the same corrosion resistance, strength and toughness as the base metal.
The welding of 2507 is not difficult, but the welding procedure needs to be designed so that after welding, it can maintain a good phase balance and avoid the precipitation of harmful metal or non-metal phases.
The presence of austenite in the structure of duplex stainless steel can reduce the brittleness and grain growth tendency of high chromium ferrite, and improve weldability and toughness.
Applications
