At AB Sandvik Steel the corrosion behavior of stainless steel grades is tested in our own laboratories, at institutes and in actual process environments at customers. Data is continuously evaluated and compiled at the R&D Centre. As an example, these data are presented in the Sandvik Steel Corrosion Handbook, compiled in co-operation with Avesta Sheffield AB. In 1999 a new edition of the corrosion handbook has been published. To the corrosion tables new data have been added and the text part of the handbook has been enlarged.

Duplex stainless steels have proved to be cost-effective problem solvers in a large number of corrosive applications. The family of the duplex grades SAF 2304, SAF 2205 and SAF 2507 (UNS S32304, S31803 and S32750) has different technical profiles and cover a large range of industry applications. This paper summarizes the most characteristic corrosion properties of duplex stainless steels.

One interesting environment for duplex stainless steels is in organic acids. Laboratory tests have been used in order to evaluate the influence of chlorides, temperature, acid concentration and various contaminants in acetic acid and formic acid. The results show that duplex stainless steels are very resistant to organic acids, also in presence of various contaminants, and also that their resistance in some cases is comparable to or even better than for high alloyed austenitic stainless steels and Ni base alloys. The range of application in organic acids has been clearly determined, with well defined temperature and concentration ranges for the use of duplex stainless steels in various organic acids.