Stainless steel
Stainless steels have a long history of application in contact with water due to their excellent corrosion resistance. Applications include a range of conditions from plumbing, potable and waste water treatment to desalination. Types 304 and 316 stainless steels are standard materials of construction in contact with water. However, with increasing chloride contents higher alloyed stainless steels such as Type 2205 and super austenitic and super duplex stainless steels are utilized.
Stainless steel
Duplex stainless steels have a mixed microstructure of austenite and ferrite, the aim usually being to produce a 50/50 mix, although in commercial alloys the ratio may be 40/60. They are characterized by high chromium (19–32%) and molybdenum (up to 5%) and lower nickel contents than austenitic stainless steels. Duplex stainless steels have roughly twice the strength compared to austenitic stainless steels. Their mixed microstructure provides improved resistance to chloride stress corrosion cracking in comparison to austenitic stainless steels Types 304 and 316.