Effect of Final Rolling Temperature on Microstructure and Corrosion Resistance of Sn-Containing Ferritic Stainless Steel

The hot rolling (starting rolling temperature of 1 150 ℃, and final rolling temperatures of 730,800,870,940 ℃) and annealing (950 ℃×5 min), and cold rolling and annealing (900 ℃×2 min)treatments were carried out on the smelting Sn-containing ferritic stainless steel. The effects of final rolling temperature on the microstructure of the cold rolled annealed sheet, the corrosion resistance to H₂SO₄ and FeCl₃ and electrochemical properties were studied. The results show that the microstructures of the cold rolled and annealed sheet at different final rolling temperatures were composed of γ fibre recrystallized grains. With the decrease of the final rolling temperature, the grain size of cold rolled and annealed Sn-containing ferritic stainless steel sheets decreased. When the final rolling temperature was 800 ℃, the grain size was 10-20 μm, and the size distribution was the most uniformly. With the decrease of final rolling temperature the resistance to H₂SO₄, FeCl₃ corrosion and electrochemical corrosion rate decreased first and then increased, and when the finish rolling temperatures was 800 ℃, both achieving the minimum values.