To effectively manufacture a hot-rolled steel material having a good surface property by suppressing the generation of surface defects due to Ni concentration or the like.
In the manufacturing method of a hot-rolled steel sheet, primary descaling (a1) and finishing descaling (a2) are respectively performed at a heating furnace outlet side and a finishing mill row inlet side by high-pressure water jetting. The primary descaling (a1) is performed between the primary descaling (a1) and finishing descaling (a2) in a line direction, and descaling (aX) is performed at intervals of 15 m or more with respect to the finishing descaling (a2) and at six spots or more at intervals of 15 m or more between the respective spots. Descaling (aX) by high-pressure water jetting is performed at six times or more at predetermined intervals, thereby dramatically improving a removal effect of an Ni-concentrated layer and properly oxidizing and removing the Ni-concentrated layer.
HOSHI TORU
INOUE TADASHI
KAMIOKA SATOSHI
FUJIBAYASHI TERUO
| JPS61269925A | 1986-11-29 | |||
| JP2006181612A | 2006-07-13 | |||
| JP2006247714A | 2006-09-21 | |||
| JPH06114432A | 1994-04-26 |