Double shielded gas tungsten arc welding （GTAW, also known as tungsten inert gas （TIG） welding） of an SUS304 stainless steel with pure inert argon as the inner layer shielding and the At-CO2 or CO2 active gas as t...Double shielded gas tungsten arc welding （GTAW, also known as tungsten inert gas （TIG） welding） of an SUS304 stainless steel with pure inert argon as the inner layer shielding and the At-CO2 or CO2 active gas as the out layer shielding was proposed in this study to investigate its effect on the tungsten electrode protection and the weld shape variation. The experimental results showed that the inner inert argon gas can successfully prevent the outer layer active gas from contacting and oxidizing the tungsten electrode during the welding process. Active gas, carbon dioxide, in the outer layer shielding is decomposed in the arc and dissolves in the liquid pool, which effectively adjusts the active element, oxygen, content in the weld metal. When the weld metal oxygen content is over 70×10-6, the surface-tension induced Marangoni convection changes from outward into inward, and the weld shape varies from a wide shallow one to a narrow deep one. The effect of the inner layer gas flow rate on the weld bead morphology and the weld shape was investigated systematically. The results show that when the flow rate of the inner argon shielding gas is too low, the weld bead is easily oxidized and the weld shape is wide and shallow. A heavy continuous oxide layer on the liquid pool is a barrier to the liquid pool movement.展开更多
分析了1 100 k V气体绝缘双屏蔽复合套管各组成部分对套管电气性能的影响,建立数学模型,利用ANSYS软件对复合套管电场分布进行了计算与优化,优化结果表明,在雷电冲击电压下,套管各部分电位分布均匀,套管内部及绝缘子表面场强满足理论要...分析了1 100 k V气体绝缘双屏蔽复合套管各组成部分对套管电气性能的影响,建立数学模型,利用ANSYS软件对复合套管电场分布进行了计算与优化,优化结果表明,在雷电冲击电压下,套管各部分电位分布均匀,套管内部及绝缘子表面场强满足理论要求且裕量充足。该产品已通过全部型式试验,满足了各项技术指标及工程需要。展开更多
基金supported by the National Science Foundation of China under Grant No.50874101the Science Program of Shenyang City under Grand No.1071275-0-02
文摘Double shielded gas tungsten arc welding （GTAW, also known as tungsten inert gas （TIG） welding） of an SUS304 stainless steel with pure inert argon as the inner layer shielding and the At-CO2 or CO2 active gas as the out layer shielding was proposed in this study to investigate its effect on the tungsten electrode protection and the weld shape variation. The experimental results showed that the inner inert argon gas can successfully prevent the outer layer active gas from contacting and oxidizing the tungsten electrode during the welding process. Active gas, carbon dioxide, in the outer layer shielding is decomposed in the arc and dissolves in the liquid pool, which effectively adjusts the active element, oxygen, content in the weld metal. When the weld metal oxygen content is over 70×10-6, the surface-tension induced Marangoni convection changes from outward into inward, and the weld shape varies from a wide shallow one to a narrow deep one. The effect of the inner layer gas flow rate on the weld bead morphology and the weld shape was investigated systematically. The results show that when the flow rate of the inner argon shielding gas is too low, the weld bead is easily oxidized and the weld shape is wide and shallow. A heavy continuous oxide layer on the liquid pool is a barrier to the liquid pool movement.
文摘分析了1 100 k V气体绝缘双屏蔽复合套管各组成部分对套管电气性能的影响,建立数学模型,利用ANSYS软件对复合套管电场分布进行了计算与优化,优化结果表明,在雷电冲击电压下,套管各部分电位分布均匀,套管内部及绝缘子表面场强满足理论要求且裕量充足。该产品已通过全部型式试验,满足了各项技术指标及工程需要。
