Method of continuous hot rolling and apparatus for welding steel bars thereof

摘要

Sheet bars are effectively joined while they are traveling and subjected to continuous hot rolling without causing defects in quality and without requiring large expensive apparatus such as a swing roller etc. The present invention is to provide a continuous hot rolling method and apparatus in which the tail of a preceding sheet bar is butted to the top of a succeeding sheet bar between the rough and finishing mills on a continuous hot rolling line, and the butted portion is welded from the upper surface of the sheet bars by means of laser beam or plasma arc while the sheet bars are traveling. According to the present invention, it is possible to join sheet bars from the upper surface in a short period of time without stopping the sheet bars and without causing splashes and burrs, before the sheet bars are subjected to continuous finish rolling. Since the welded apparatus does not interfere with the sheet bar conveyance table, hot strips of high quality can be effectively manufactured by the economical apparatus.