Method and device for removing and suppressing scale of metal material

摘要

Suppression and removal of scales are efficiently carried out in a steel material hot rolling process and the time of pickling treatment as a successive step is largely shortened. In a water cooling step of metallic material 11 at a temperature of 100 DEG to 1,200 DEG C, scales are removed by applying a direct current or an alternating current to metallic material 11 at 0.1 to 10<5> A/m <2> of unit surface area from pinch rolls 2 to rolls 6 or apron guides 7 on the outlet side of a hot rolling mill 1 and/or by injecting cooling water at a pH value of -2 to 4 onto the metallic material 11 front cooling headers 4 and apron guides 7.