A duplex stainless steel for use in urea manufacturing plants, in mass %,
consisting of C: 0.03% or less, Si: 0.5% or less, Mn: 2% or less, P:
0.04% or less, S: 0.003% or less, Cr: 26% or more, but less than 28%, Ni:
6-10%, Mo: 0.2-1.7%, W: more than 2%, but no more than 3%, N: more than
0.3%, but no more than 0.4%, with the balance being Fe and impurities, in
which the content of Cu as an impurity is not more than 0.3%. The duplex
stainless steel may also have Ca, Ce, and B content, and it is desirable
that levels of Al and O (oxygen) as an impurities be no more than 0.05%
and 0.01% respectively. Further, it is preferable that an increase in the
Vickers hardness of the steel should not be more than 80, before and
after the solution treated steel is subjected to the heat treatment of
800.degree. C. for 30 minutes and subsequent water cooling. This duplex
stainless steel possesses a high corrosion resistance.