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Heat transfer in GTA welding arcs

Posted on:2013-05-22Degree:M.SType:Thesis
University:Montana Tech of The University of MontanaCandidate:Huft, Nathan JFull Text:PDF
GTID:2451390008972663Subject:Materials science
Abstract/Summary:
Heat transfer characteristics of Gas Tungsten Arc Welding (GTAW) arcs with arc currents of 50 to 125 A and arc lengths of 3 to 11 mm were measured experimentally through wet calorimetry. The data collected were used to calculate how much heat reported to the cathode and anode and how much was lost from the arc column. A Visual Basic for Applications (VBA) macro was written to further analyze the data and account for Joule heating within the electrodes and radiation and convection losses from the arc, providing a detailed account of how heat was generated and dissipated within the system. These values were then used to calculate arc efficiencies, arc column voltages, and anode and cathode fall voltages. Trends were noted for variances in the arc column voltage, power dissipated from the arc column, and the total power dissipated by the system with changing arc length. Trends for variances in the anode and cathode fall voltages, total power dissipated, Joule heating within the torches and electrodes with changing arc current were also noted. In addition, the power distribution between the anode and cathode for each combination of arc length and arc current was examined.;Keywords: Gas Tungsten Arc Welding, GTAW, anode fall, cathode fall, heat transfer, wet calorimetry.
Keywords/Search Tags:Heat transfer, Gas tungsten arc welding, Cathode fall, Arc current, Wet calorimetry, Arc column, Total power dissipated
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