Passivation is the process of forming a protective oxide film on stainless steel. It is accomplished through an appropriate inline bright annealing process. Duplex stainless steel exhibits optimum mechanical and corrosion properties with the austenite-ferrite phase balance in its structure. However, the ferrite-austenite equilibrium in duplex structure can also be affected by inline bright annealing process, in which the heating of stainless steel to a suitably high temperature in a reducing atmosphere takes place. For this reason, the effect of inline bright annealing process on the microstructure and mechanical properties of TIG welded AISI2205 stainless steel tube was evaluated in this study. The results point out that the structure and mechanical properties of the duplex stainless steel tube are affected by the inline bright annealing process. In light of foregoing findings, the sample that was inline bright annealed in reducing nitrogen gas atmosphere has given optimum mechanical properties.