Hot rolled fine steel mfr. - in which thin slab is taken up from continuous casting to be wound in hot box to be further rolled in reverse direction in CSP working stages

摘要

To produce hot rolled steel strip from continuous casting esp. fine steel, heat is applied in the successive stages of a compact strip prodn. process (CSP). The material is roughed down in a sequence of n-1 passes in a rolling train of n stands, with the first stand moved up in the rolling direction. The roughed down strip is simultaneously wound at the end of the rolling train into a coil to be held in a hot box to maintain the temp. The first stand is returned and the other stands changed to operate the rolling train in reverse. The strip is unwound from the coil and passed through the rolling train in n passes, with the final stand moved in, in the rolling direction. Pref. a thin slab is passed from the compensating furnace to a ferry which carries it from its start point in line with the continuous casting assembly, to one side on a line parallel to the rolling train. At the same time, or slightly before, a part of the ferry which is formed as a roller path accelerates the slab into the rolling train. The rolling train converts the slab into a strip which can be wound and, at the end, the strip is wound and held in a hot box to prevent temp. loss. The roller path is retracted ino the ferry, which then returns to its start position. The rolling train is set for a reverse operation, the wound strip is uncoiled and passed back through the rolling train to be further wound into a coil and stored. The thin slab of fine steel is rolled with pref. five passes and then with a further five passes in the reverse direction. ADVANTAGE - The technique can be used for steels of different qualities, and different programmable final dimensions. Roller wear is reduced, when rolling fine steels and the system also avoids excessive scaling when working carbon steels, which would affect the surface quality.