目前 ,具有最高ｒ值的冷轧板是将含Ｎｂ、ＴｉＩＦ钢的Ｃ含量降至 2× 1 0 -5 ,用连续退火工艺生产得到的ＥＤＤＱ材 ,其ｒ值为 2 2 ,可广泛用于汽车各部位。但是 ,对于油盘和侧外板等复杂、宽幅的一体化板 ,要求具有比ＥＤＤＱ材更高的ｒ值。为此 ,川崎钢铁公司开发了超高 ｒ At present, the cold rolled sheet with the highest r value is obtained by reducing the C content of the Nb-containing and TiIF steels to 2 × 10 -5. The EDDQ material produced by the continuous annealing process has an r value of 22 and can be widely used Various parts of the car. However, for complex, wide-width, integrated panels such as oil pan and side panels, higher r-values ​​than EDDQ materials are required. To this end, Kawasaki Steel developed ultra-high r