Recent progress in the technology for IF steels

The controlling factor of surface defects occurring in continuous casting is described in terms of the Ti and Nb effect. IF steel produced by thin slab casting process is introduced. IF treated steel produced from scrap is suggested as an alternative to producing a new kind of steel sheet. The effects of Nb in the batch annealing process and galvannealing process are described. A new IF steel coated with Sn-Zn eliminating Pb was developed for gasoline tank of cars. (AU)