904l stainless steel sheet is a superaustenitic stainless steel that is created for moderate to high corrosion resistance in a wide range of environments. The mixture of chromium and nickel content, with the additions of molybdenum and copper provides excellent corrosion resistance.Due to nickel 25% and molybdenum 4.5%, ASTM B625 UNS N08904 provides good chloride stress corrosion cracking resistance, pitting and general corrosion resistance which are superior to 316L and 317L. It is develop to out-break environments containing dilute sulphuric acids. 904l stainless steel plate has good resistance to inorganic acids such as hot phosphoric acid. It can be easily welded and processed by standard fabrication process. ss 904l plate is quite ductile and can be easily formed. The addition of molybdenum and nitrogen provides more powerful processing equipment and it may be necessary when compared to the standard 304/304L grades. astm a240 type 904l has excellent resistance to warm seawater and chloride attack. The high resistance of it is against stress corrosion cracking and it is due to the presence of high amounts of nickel in its composition. Moreover, the addition of copper develops resistance to sulphuric acid and other reducing agents in both aggressive and mild conditions.1.4539 plate material, offers good oxidation resistance. However, the structural stability of this grade collapses at high temperatures, particularly above 400°C.ASTM A240 UNS N08904 material can be solution heat-treated at 1090 to 1175°C by following by rapid cooling method. Thermal treatment is suitable for hardening it. 1.4539 sheet major applications are oil refinery equipment, Pulp and paper processing industries, gas scrubbing plants, etc.