Study on the Gas Pressure Welding (2nd Report)

Welding of mild steel rods and pipes

Abstract

The author wrote in the 1st report on the welded strength of joint made by the gas pressure welding method under the most favourable conditions and in the present paper discusses applicability of this process in the field. It is learned as a result that, if only the upset surfaces are perfectly cleaned of rust, the welded strength will be sufficient.
For testing the welded part, from the standpoint of principle, magnaflux method was found the most reliable among the metallurgical, supersonic and magnaflux tests.
As the first experiment of welding different metals, the writer joined steels with different carbon contents and gained almost ideal results, so he proceeded to apply his method to the welding of mild steel with satisfactory results.
Open butt welding, one of the gas pressure welding methods, was also studied and it was found that unless the joining parts were massive enough, this was inferior in may respects to closed butt welding.
Further he carried out the welding of piges and found that when the ring burner was usedand the joining surface properly beveled before welding, all the ruptures of welded pipes occuredubytension test in the moter part, not on the weld;and as the appearance of the inner part of the welded pipe was very good, it would never offer any resistance to the flowing fluid.
Moreover, from the principle used, high degree of air and water-tightness might well be expected and this was also ascertained by experiment.
And this process, in actual operation, does not necessitate any packing of welding pipes witn reducing gas, e. g., H₂, for an oxy-acetylene flame is itself reducing.
Through the foregoing discussions, it was confirmed that closed butt gas pressure welding was one of the most reliable methods for the welding of rods and pipes.