Development of Galvannealed High-strength Steel Sheets with Deep Drawability

摘要

It is important to improve (1) Lankford value adn (2) the wetting characteristics with molten zinc for the development of galvannealed high-strenght IF-steels with deep drawability corresponding to the demand of weight reduction and high corrosion resistance in automotive panels. Concerning item (1), the effect of coiling temperature after hot rolling on Lankford value and recrystallization texture of annealed steels was investigated together with basic research on hot-rolled microstructure and texture. In addition metallurgical factros related to Lankford value was considered. Concerning item (2), the effect of reduction heating ocnditions before dipping on zinc wettability was studied. Finally mechanical and antipowdering properties of the developed products are described.