Thermal effects of gas tungsten arc welding for thick copper plates at different welding condition

To improve the weldability of thick copper plates, the welding temperature patterns of gas tungsten arc welding for thick copper plates were simulated by the commercial finite element software Marc, and the effects of different welding currents and different preheating temperatures on the size of weld pools and heat-affected zones were discussed. Results show that both the weld pools and the heat-affected zones increase with the increasing preheating temperatures or welding currents. Weld pools with the same size can be obtained by combining different welding currents and preheating temperatures, while the sizes of their heat-affected zones are different very much. The sizes of weld pools obtained by He or N₂ arc welding at 20°C come up to those obtained by Ar arc welding at the preheating temperature of 400°C, and the heat-affected zones are narrower than those obtained by Ar arc welding at the preheating temperature of 400°C.