2507 is a more advanced duplex stainless steel than 2205 or 31803. Generally speaking, it is difficult to say that one material is better or more advanced than another material, but I think we can say that 2507 is more advanced than 2205 or 31803.
origin of name
2507 is the name we usually call this material. This name is used all over the world. However, when we searched for formal information, we found that the brand number 2507 could not be found. This material brand was first developed abroad. To understand the origin of its name, we still need to understand what countries around the world call this material.
In foreign American standards, 2507 is called UNS S32750; in Chinese standards, it is called S32750 or S25073 or 00Cr25Ni7Mo4N. Then someone may ask, is it the abbreviation of the Chinese standard S25073? Because the Chinese standard for 2205 has S22053. However, the author believes that the origin of the name 2507 is not the source of the national standard. As mentioned above, there are also expressions of 2205 and 2507 abroad. The author believes that these two naming methods mainly come from Sandvik's two products SAF2205 and SAF2507. According to Sandvik's duplex stainless steel product naming method, 22 and 25 are the content of chromium and Cr elements respectively, and 5 and 7 are the content of nickel and Ni elements respectively. Therefore, the author believes that 2205 and 2507 are derived from the names of these two brands. Law.
chemical composition
Compared with 2205, 2507 has a higher CrNiMoN content, a small amount of Cu is added, and the Mn and Si contents are reduced. It can be inferred from the chemical composition alone that 2507 has better resistance to uniform corrosion and localized corrosion.
Main performance and industry applications
Some readers previously asked under the 2205 article whether 2205 materials can be used under specific working conditions. Since such questions require detailed technical working conditions, interested readers can leave a comment or send me a private message on Baidu APP.
2507 has all the superior properties of 2205, and its strength and corrosion resistance are even better. The only difference is that the ferrite content of 2507 is more difficult to control. Generally speaking, the ferrite content of well-made 2205 can be controlled at 40% to 60%, while the ferrite content of 2507 can be controlled at 35% to 65%. Of course, this is only a requirement in specific industry specifications. There is no such requirement in the general production specifications for duplex stainless steel.
The main applications of super duplex stainless steel 2507 are: pulp and paper industry, seawater desalination, flue gas purification, sulfuric acid, heat exchangers, chemical tanker piping systems, seawater systems, etc.