Increasing interest in duplex stainless steels is due to their ability to combine
elevated mechanical properties (strength, fatigue...) and an optimal resistance to many
types of corrosion like Stress Corrosion Cracking or Intergranular Sensitization. Given
high chromium content of the standard and super-duplex steels along with molybdenum and
nitrogen alloying additions, they also exhibit an excellent resistance to pitting and
crevice corrosion in halide-containing media generally equivalent to austenitic and
super-austenitic with similar Pitting Resistance Equivalent. Further aspects of the
question are reviewed in introduction of the present paper including passive film and
metallurgical features such as two-phase microstructure, presence of non metallic
inclusions, precipitates or intermetallic phases. Then, this work addresses the problems
of corrosion testing of duplex stainless steels. It is intended in particular to shed
light on some points of practical importance regarding electrochemical characterization
best practices. Thus, a reliable ranking of materials, including new lean grades, requires
a relevant choice of corrosion criteria and polarization methods. The determination of
both pitting potentials and critical pitting temperatures is achieved by using a
combination of several electrochemical tests based on potentiodynamic, potentiostatic as
well as galvanostatic experiments together with a statistical analysis when needed.