Recrystallisation Texture of Cold Rolled and Annealed IF Steel Produced from Ferritic Rolled Hot Strip

The ferritic rolling strategy allows for the production of two different hot strip grades, a "soft" and a "hard" hot strip. The "soft" hot strip is rolled in the upper ferrite region and a sufficiently high coiling temperature ensures direct recrystallisation in the coil. The "hard" hot strip is rolled at relatively lower temperatures in the ferrite temperature region and exhibits a strained microstructure with a desirable rolling texture. Furthermore, these ferritic rolled hot strips can be used as initial strip for subsequent cold rolling. The current investigation focuses on the development of the recrystallisation texture of cold rolled and annealed ferritic rolled hot strip for different cold reductions. For this purpose "soft" and "hard" hot strips were produced on a laboratory hot rolling mill. These strips were cold rolled with a total reduction of 40 to 80% to a final thickness of 0.5mm. Subsequently the strips were subjected to simulated continuous annealing, using a salt bath furnace. The macro texture of both types of specimens was measured and correlated to the mechanical properties, including the Lankford values. A very different development of the recrystallisation texture and hence mechanical properties has been observed. However, both grades yielded improved deep-drawing properties.