Duplex
stainless steels are two-phase alloys
based on the Fe-Cr-Ni system. The specific
advantages offered by duplex stainless
steels over conventional 300 series stainless
steels are strength (approximately twice
that of austenitic stainless steels),
improved toughness and ductility (compared
to ferritic grades), and a superior chloride
SCC resistance and pitting resistance.
The high yield strength offers designers
the use of thin-wall material (which can
lead to major reductions in weight) with
adequate pressure-containing and load-bearing
capacity. Duplex stainless steels have
found widespread use in a range of industries,
particularly the oil and gas, petrochemical,
and pulp and paper industries.
