| 摘要 |
1,207,862. Scarfing. L'AIR LIQUIDE, SOC. ANON. POUR L'ETUDE ET L'EXPLOITATION DES PROCEDES GEORGES CLAUDE. 6 Dec., 1967 [13 Dec., 1966], No. 55499/67. Heading B3V. [Also in Division F4] A method of initiating the scarfing of a workpiece 18 comprises (a) directing a scarfing torch towards the workpiece 18; (b) bringing the heating flame to the required scarfing intensity; (c) rotating the torch nozzle about an axis parallel or coincident with the nozzle; and (d) inclining the torch axis about a point 27 on the workpiece surface, the steps (b)-(d) being carried out simultaneously or successively with step (b) being carried out before step (c). The heating flame 10 of the torch is formed by a gas mixture delivered through holes 8 in a part 6, and initially the amount of cutting oxygen, delivered through a duct 4, is small or nil. The torch is rotated about its own axis and moved towards the workpiece 18 to the position 22, during which the oxygen supply may be increased to the required scarfing value. The initiation of the scarfing may be facilitated by introducing iron powder or combustible gas through a passage 14 into the flame, feeding a steel rod into the flame or using a plasma jet to heat the workpiece surface. The torch is thereafter inclined so that the angle 32 is greater than 20 degrees and the angle which the nozzle axis 26-28 forms with a straight line on the surface 18 parallel to the displacement of the workpiece is less than 50 degrees. During the inclination of the torch to the position 24, the oxygen supply is increased to the required scarfing value if it has not already attained this value. |
