The influence of shield gas compositions in argon-nitrogen, argon-oxygen , argon-carbon dioxide and argon-hydrogen systems on the arc temperature was studied by means of the spectral line intensity method . The findings in this work are as follows: 1) The arc temperature increases slightly with an increase of welding current . 2) The arc temperature does not undergo a noticeable change with arc voltage . 3) The arc temperature increases with an increase in nitrogen, oxygen, carbon dioxide and

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... drogen additions. The arc temperature in argon-hydrogen gas mixtures is highest , and the one in argon-carbon dioxide gas mixtures is lowest. 4) The arc temperature seems to be influenced by electrode materials .