To provide a flame scarfing device capable of obtaining a scarfed surface in which roughness does not occur or is small in the scarfed surface when flame-scarfing a cast steel slab, and scale-like defects do not occur in a hot rolling step even when the surface treatment is not performed again.
In the flame scarfing device 1, a pair of end walls 7 disposed between an upper block 4 and a lower block 5 form both ends, and slit-like oxygen gas ejection holes 10 are formed with upper and lower surfaces thereof formed in the upper block and the lower block, respectively. The width of a portion in the middle of the longitudinal direction of the end walls is maximum so that the width of the oxygen gas ejection holes is reduced in the middle of the flow direction of the oxygen gas ejection holes. The flame-scarfed surface is further smoothed by providing a streamline wall shape of the end walls or setting the difference between the maximum and minimum widths in the longitudinal direction of the end walls to be ≥ 5 mm and ≤ 30 mm.
YAMAOKA YUICHI
DOJO SHUNJI
MATSUZAKI TAKESHI
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