水中ガス切断法について(第1報)

抄録

Authors have been developing a consumable electrode water jet technique and automatic oxy-arc cutting technique for the underwater cutting method. But the drawback of these cutting technique is that cut surface is to be re-machined by other cutting technique for welding, and therefore studied underwater gas cutting technique in order to obtain a cut surface which is able to be welded underwater without any post machining. results obtained are as follow;
(1) With use of water curtain nozzle, flame are well stabilized without use of air as a protecting gas.
(2) For the underwater flame ignition, the new method in which spark generates near nozzle using high frequency ionizer is developed with successful result.
(3) In the underwater cutting of 9 mm to 50 mm thick mild steel, cutting speeds are almost the same compared with surface cutting.
(4) Dross which attaches to bottom side can be removed easily light hammering.
(5) Cut surface is pretty, therefore underwater butt and fillet welding can be carried out as it is, and welds show satisfactory results