焊接参数对304不锈钢激光焊接温度场分布特征的影响

Influences of Welding Parameters on Temperature Field Characteristics during Laser Welding of 304 Stainless Steels

采用红外热像测量的方法,跟踪拍摄304不锈钢激光焊接的过程,研究激光焊接参数对304不锈钢焊接温度场特征的影响。试验结果表明,激光功率一定时,随焊接速度的减小,熔化区域的长度和宽度增大,但温度场分布的基本特征未变;焊接速度一定时,随激光功率的增大,焊缝正面温度场的整体温度升高,特别是熔池后端次高温区的温度显著升高和面积显著增大,但温度场分布的基本特征未变;输入线能量相近时,高功率/高速度组合的"小孔"区域温度较高,低功率/低速度组合的次高温区域的温度较高、面积较大,但是后端焊缝区域的温度较低。

Based on infrared thermograph technique, the laser welding processes of 304 stainlesssteels were recorded to study the influences of welding parameters on temperature field characteristics. The results show that, when the laser power is constant, the lengths and the widths of the melting zone are increased with the decrease of the welding speeds, but the basic characteristic of the tempera-ture field distribution will not be changed. When welding speed is constant, wpower,the temperature of the welding seam is increased ,especially the temperature and area of sub-high temperature are increased significantly, but the distribution of temperature is invariable. When the energy input is close to each other,the ＂keyhole＂ temperature of the high power/high speed com-bination is higher. Meanwhile, the temperature and area of the sub-high temperature zone in the com-bination of low power/low speed is higher, but it has a lower temperature at the back of the weld than the combination of high power/high speed.