The advantages of arc welding with bare wires and CO2 shielding gas are well known. The process has, however, certain limitations: The weld surface is not always smooth and even. The bead reinforcement is often excessive, and too convex. In the case of both butt and fillet welds, a notch effect and thus stress concentrations will be produced, representing a considerable hazard under dynamic load conditions. There is relatively excessive spatter, which either spoils the appearance or is removed at some expense. In the course of automatic welding, continuous cleaning of the nozzle will impair production continuity. The Charpy V impact strength of the weld metal, at low temperature, depends to a significant degree on the welding parameters. Unfavourable welding parameters can equally well produce welds of high brittle fracture susceptibility. In order to eliminate the above disadvantages, while maintaining the advantages of CO2 shielded welding, flux-cored wires with CO2 gas shielding have been developed. However, there is less data available about the brittle fracture behavior of such weld metals, particularly at low temperature, and also the effect of welding parameters, including the number of passes. For this reason, the notch toughness of weld metals produced using different parameters by means of CO2 shielded flux-cored wires was studied. The most favourable welding properties and weld metal toughness may be obtained with both the 15-10 and 15-18 Tubular electrody types, by applying 2- or 3-pass weld metals with a 250 to 350 Amp. current. Single-pass weld metals are less advantageous because of their dendritic and anisotropic texture, while the 4- or 5-pass welds are similarly less favorable since slag removal is rather difficult at the welding settings used.

  • Corporate Authors:

    Elektriska Svetsning Aktiebolaget

    P.O. Box 8850
    S-402 71 Goteborg 8,   Sweden 
  • Authors:
    • Konkoly, T
  • Publication Date: 1976

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Filing Info

  • Accession Number: 00131937
  • Record Type: Publication
  • Source Agency: Elektriska Svetsning Aktiebolaget
  • Files: TRIS
  • Created Date: May 14 1976 12:00AM