"Duplex"
describes a stainless steel series that is neither completely austenitic like 304 stainless steel nor pure
ferrite like 430 stainless steel. The structure of 2205 duplex stainless steel consists of an austenite
molten pool surrounded by a continuous ferrite phase. In the annealed state, 2205 contains about 40-50%
ferrite. 2205 is usually called the workhorse grade and is the most widely used grade in the duplex
stainless steel series. Duplex 2205 stainless steel (ferrite and austenite) is widely used in applications
requiring good corrosion resistance and strength. S31803 grade
stainless steel has
been modified many times to form UNS S32205, which was approved in 1996. This grade of stainless steel has
higher corrosion resistance.
At
temperatures above 300 ¡æ,brittle micro-components of this grade will precipitate,while at temperatures
below -50¡æ,these micro-components will undergo a transition from toughness to brittleness.Therefore,this
grade of stainless steel is not suitable for use at these temperatures.
What
are the characteristics of Duplex 2205?
High
resistance to chloride stress corrosion cracking
Resistant
to chloride pitting and crevice corrosion
Good
general corrosion ressistance
Good
resistance to sulfide stress corrosion resistance
High
strength
Good
weldability and workability