Fabrication of Fe–Cr–Al base alloy strips by melt dragging and their oxidation resistance at elevated temperature

Fe–Cr–Al–Ti–MM (MM: misch metal) alloy strips for a metal catalytic converter substrate in automobiles were prepared by a melt drag casting (MDC) process. The strips of 100 mm width and 90–200 μm thickness were cold-rolled down to 40 μm in thickness with an annealing treatment. In this study, the effect of casting variables on the strip thickness was observed. It is found that the dependence of the strip thickness on casting variables can be expressed in terms of the contact time between melt and casting roll surface, and it can be expressed as follows: thickness (μm)=K{contact time (s)}1/2. The microstructure of the melt-dragged strip consisted of two layers, i.e., equiaxed and columnar grain zones. And, the melt-dragged Fe–20Cr–5Al–MM alloy strip showed a better cyclic oxidation resistance at elevated temperature than the conventionally cold-rolled strip.