| 摘要 |
PURPOSE:To obtain a wire which contains nitrogen at a low ratio and can contribute to a remarkably improvement in the toughness of a weld metal by adding and packing simultaneously dry ice powder into a coiled steel pipe in the stage of packing a flux into said pipe. CONSTITUTION:The flux 8 is dropped from a flux hopper 9 through a flux charging pipe 1 provided to the top end of a steel pipe 4 wound like a coil on a large-sized spool 6 made of steel and is packed into said steel pipe. On the other hand, the dry ice powder 10 is dropped via a hopper 11 from the point near the top end of the pipe 1 and is injected into said pipe. The flux 8 and the dry ice 10 can be thereby continuously supplied into the pipe 4 at a specified ratio. The size of the dry ice is preferably about 0.5-2mm and the rate of the dry ice to be incorporated with respect to the flux is preferably about 0.2-2.0wt% in order to remove effectively the air in the pipe by the gas converted to CO2 in the pipe. The wire obtd. in such a manner contains nitrogen just at a low ratio and yields the weld metal having good toughness.
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