This paper gives two examples of the recent use of new stainless steels in desalination water industry. The first concerns the materials used for the walls of thermal process evaporation cells. In the past, carbon steel, clad steels, copper-nickel alloys, or austenitic stainless steel grades such as 316L were the primary recommended materials. More recently the duplex grades UNS S32304 and UNS S32205 have been selected for this application. This paper provides some of the technical reasons, which brought about this change in the choice of materials selected. Initially, the results of an extensive corrosion study, performed in a representative environment for evaporation cells and including both duplex and austenitic grades, are presented and discussed. Then a joint corrosion testing program conducted in cooperation with a well established desalination plant designer and run under actual plant conditions is outlined. The results of these field tests led to the development of a new concept for evaporation cells based on utilizing duplex stainless steels. In the second part of the paper, the properties of the new lean duplex UNS S32202 are presented and compared with those of 304L. Potential applications in moderately aggressive environments, such as potable or drinking water, are discussed.

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• Industeel

• Alloy Steel

• Desalination

• Corrosion

• Article