1. General corrosion: The higher chromium and molybdenum content of SAF2507 double stainless steel makes it strong overall corrosion resistance against organic acids such as formic acid and acetic acid. SAF2507 double stainless steel alloy has strong corrosion resistance of inorganic acids, especially inorganic acids containing chloride. Compared to the 904L, SAF2507 double stainless steel has a higher corrosion resistance of diluted sulfuric acid mixed with chloride ions. The 904L is an austenitic alloy designed to resist corrosion by pure sulfuric acid. Grade 316L cannot be used in a hydrochloric acid environment, it may suffer local corrosion or general corrosion. SAF2507 can be used in a diluted hydrochloric acid environment and has high resistance to point damage and crack corrosion.
2. Intergranular corrosion The low carbon content of nSAF 2507 greatly reduces the risk of carbide precipitation in the intergranular during heat treatment, so this alloy has a great ability to resist intergranular corrosion related to carbide. Corrosion cracking under stress The duplex structure of the SAF2507 makes it strongly resistant to stress corrosion cracking. Due to its higher alloy content, the corrosion and strength resistance of SAF2507 are better than 2205. There are many ways to test the corrosion resistance of steel products in solutions containing chlorides The above data are based on the electrochemical technology mentioned in ASTMG61. The critical corrosion temperature of high-performance stainless steel is specified in a 1M sodium chloride solution.
3. Crack corrosion: Cracks are almost inevitable in construction and other aspects, which makes stainless steel more susceptible to corrosion in the chloride environment. SAF 2507 has strong crack corrosion resistance. The critical temperature of SAF 2507 and other high-performance stainless steel crack corrosion products is shown in the figure above. The iso-corrosion curve in sulfuric acid containing 2000 ppm of chloride ion is 0.1 mm / year. The iso-corrosion curve in hydrochloric acid is 0.1 mm / year. The point line represents the boiling point. At 1mNACI, the critical corrosion temperature of various alloys is the critical crack corrosion temperature of various alloys at 10% FeCl3.
