METHOD AND DEVICE FOR DESCALING STEEL MATERIAL

PURPOSE:To perform descaling always under the optimum conditions regardlessly of the feeding speed of a steel material, by traversing an injection nozzle for providing a descaling water flow, in the direction intersecting with the direction of material feeding in accordance with the feeding speed of a steel material. CONSTITUTION:A highly pressurized water header 4 which has jetting nozzles 5 and is provided to 4 positions around a steel material W are reciprocated in the direction perpendicular to the advancing direction (alpha) of the material W within a range S slightly larger than the width (w) of the material, to make the flow velocity of a jetting water flow 6 to the maximum fixed value during the reciprocation. A square column-shaped deflector plate 7 equipped with an aperture 8 having the width (b) slightly larger than the (w) and situated between the nozzles 5 and the material W is advanced and retreated along the direction (alpha) and to stop at its advancing and retreating position. The water flow 6 begins to splash on the corner of the material at the end A of the range S, and misses the material at the other end B. When the motions of the header 4 and the plate 7 are repeated respectively as shown by a figure and the velocities of the header 4 and the material W are denoted as (u) and (v) respectively while the plate 7 is advanced and retreated, a relative moving velocity (r) of the water flow 6 to the surface of the material W is given by the vector difference between the (u) and (v), and the (u) is controlled in accordance with the (v) so that it coincides with the maximum target speed which provides a descaling action at the velocity (r).