Development of a Bar-joining Apparatus for Endless Hot Rolling

Endless hot rolling is a production process for finish rolling, that is carried out in a bath-less manner, while contributing to higher productivity and yield. Bar joining prior to finishing rolling is one of the key technologies for endless rolling. In contrast to the conventional method, in which the areas to be joined are heated and then joined together, Mitsubishi-Hitachi Metals Machinery (MH), Inc. and POSCO have recently developed a unique solid-state joining process capable of joining bars very quickly (in less than 0.5 seconds) and reliably without a special heating process. An apparatus using this new joining process has been incorporated into the No. 2 hot rolling mill at the POSCO Pohang Works, where full-scale endless hot rolling is already in operation.