An Improved Simulation of Heat Transfer and Fluid Flow in Plasma Arc Welding with Modified Heat Source Model
A three dimensional numerical model is developed to investigate the plasma arc welding (PAW) process, featured by the compound volumetric heat source movement and heat transfer with phase change in the weld pool, where fluid flow is driven by a combination of surface tension, electromagnetic and buoyancy forces. Based on the actual configuration of PAW welds, a modified heat source model is proposed to involve the key-holing effect of PAW. It is composed of a double-ellipsoidal volumetric heat source at the upper and a conical volumetric heat source at the lower. It is proven that the modified heat source model as well as fluid flow consideration can improve the PAW simulation. The predicted weld bead is in good agreement with the experimental results, along with the hump in the fusion line. The effect of fluid flow in molten pool is indicated to be non-negligible. In addition, the evolution of the weld pool is presented along with the temperature field and velocity field. A discussion is made on the process parameters such as plasma arc power and welding speed. It turns out that high plasma arc power or/and low welding speed is beneficial to complete joint penetration, but optimum process parameters are good choice to ensure both the high weld quality and complete joint penetration.
PAW modified heat source weld pool surface tension fluid flow hump
Yan Li Yan-Hui Feng Xin-Xin Zhang Chuan-Song Wu
School of Mechanical Engineering, University of Science and Technology Beijing, Beijing 100083, Chin School of Materials Science and Engineering, Shandong University, Jinan 250061, China
国际会议
济南
英文
1-18
2012-08-24（万方平台首次上网日期，不代表论文的发表时间）