| 摘要 |
Annealing takes place continuously. The temperature is raised above the eutectic temperature of the steel, the steel is then held above this temperature for more than 10 s, and then rapidly cooled to below 350 degrees C at more than 100 degrees C/s. Production of the steel strip involves: (a) providing a hot-rolled steel strip containing (in wt.%) 0.040-0.080 C, 0.35-0.5 Mn, 0.040-0.070 Al, 0.0035-0.0060 N and the remainder Fe and inevitable impurities; (b) primary cold rolling of the obtained strip; (c) annealing the cold rolled steel strip; and (d) secondary cold rolling of the annealed steel strip. An Independent claim is included for the steel strip produced by the above process. In an aged state, its ultimate elongation is expressed in terms of the ultimate tensile strength by an equation. |
