Exothermically assisted shielded metal arc welding
Heat input, which is most often directly related to electrical energy input, controls weld bead morphology and the evolution of microstructure. Exothermic reactions have been found to increase the heat input available during shielded metal arc (SMA) welding. The work presented in this paper was performed to determine how much heat can be attained from exothermic reactions and determine the influence of this additional heat on weld deposition. Consumable SMA welding electrodes were produced with reagents added to the flux coating. The flux additions to promote exothermic reactions consisted of magnesium plus hermatite (Fe{sub 2}O{sub 3}), aluminum plus hermatite, and a 50-50 wt% aluminum-magnesium alloy plus hermatite. With calorimetry, increasing concentrations of exothermic promoting additions were found to produce an increase in the effective heat input. Electrodes with sufficient exothermic additions were found to product 25{emdash}30% of the heat necessary for welding. Finally, the efficiency of the shielded metal arc welding process was determined with and without the reagent. Analysis of energy generation and utilization was performed to evaluate the use of pyrochemical flux reactions to produce exothermically assisted consumables. A model ha been developed to assist in the formulation of exothermically assisted SMA electrodes.
- OSTI ID:
- 115501
- Report Number(s):
- CONF-9404233-; TRN: 95:002927-0079
- Resource Relation:
- Conference: 75. American Welding Society (AWS) annual meeting, Philadelphia, PA (United States), 10-15 Apr 1994; Other Information: PBD: 1994; Related Information: Is Part Of 75th Diamond anniversary American Welding Society annual meeting; PB: 273 p.
- Country of Publication:
- United States
- Language:
- English
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