Stabilisation of ferritic stainless steels with Zr and Ti additions

Traditional 11.5 wt-% Cr ferritic stainless steels are single stabilised with Ti or dual stabilised with Ti-Nb additions. A dual-stabilised ferritic stainless steel 409 with Zr-Ti additions was studied, which was selected through thermodynamic and kinetics analysis. The alloy was subjected to thermomechanical processing using both hot and cold rolling and annealing. The intergranular corrosion resistance and microstructure of this alloy was evaluated. Of particular interest was to study the stabilisation behaviour of this alloy under all processing conditions. The results showed that the precipitation of CrxCy was effectively prevented; hence, the alloy used in this investigation had an excellent resistance to intergranular corrosion.