METHOD FOR MECHANICALLY DESCALING STEEL MATERIAL

PROBLEM TO BE SOLVED: To provide a descaling method by which both ordinary oxidized scale which is generated when heating the steel material containing Si, Cr or Ni up to the hot-rolling temperature range and composed of three layers and a sub-scale which is generated on the interface of the oxidized scale and a base steel and difficult to be peeled can be efficiently removed in both aspects of equipment and energy consumption. SOLUTION: In this descaling of the steel material for hot rolling containing at least one kind of Si, Cr and Ni of ≥0.1%, mechanical descaling is performed at the surface temperature of ≥900°C after heating the steel material at the atmospheric temperature of ≥1,200°C in a heating furnace. Under such mechanical descaling conditions, the porosity of the sub-scale is increased, the sub-scale is made into more porous structure or the rate of decrease of the hardness of the scale is increased. Then, the sub-scale is easily destroyed and peeled with a brush roll. COPYRIGHT: (C)2007,JPO&INPIT