| 摘要 |
<p>PURPOSE:To omit a burring work and to improve the quality of a rolling stock by providing a torch cutting a metal material and by forming a negative pressure by blowing a gas around a generating slag. CONSTITUTION:A nozzle 10 is provided on a supporting arm 11 with the gas exhaust port facing toward the lower part, the feed pipe 14 of nitrogen gas is fixed via a link arm 14 to the supporting arm 11 and a nozzle 15 is arranged by intersecting at right angles with the injection direction of the torch 10 at the tip thereof. A slab 16 is melted by injecting and burning an oxygen gas from the torch 10 and on the other hand from the nozzle 15, a nitrogen gas is blown out with the prescribed pressure. In this case a negative pressure is formed near the generated slag by the nitrogen gas flow, sucking the slag by its collection to the lower part. In this way the formation of burrs on the lower face of the slab 16 can be prevented. Consequently the quality of the rolling stock of the slab 16 can be improved as well as the abbreviation of burring work.</p> |
