Plasma keyhole welding of a workpiece using a process gas, comprises temporally changing the gas volume flow rate and/or gas composition of the process gas during a welding process as a function of a basic condition of the welding process

摘要

The method for plasma keyhole welding of a workpiece (8) using a process gas provided with a gas volume flow rate, comprises temporally changing the gas volume flow rate and/or gas composition of the process gas during a welding process as a function of a basic condition of the welding process, where the basic condition is characteristics of the workpiece and/or parameters of the welding process. The parameters of the welding process and/or the characteristics of the workpiece are determined by optical, pneumatic and/or electric characteristics of the plasma jet. The method for plasma keyhole welding of a workpiece (8) using a process gas provided with a gas volume flow rate, comprises temporally changing the gas volume flow rate and/or gas composition of the process gas during a welding process as a function of a basic condition of the welding process, where the basic condition is characteristics of the workpiece and/or parameters of the welding process. The parameters of the welding process and/or the characteristics of the workpiece are determined by optical, pneumatic and/or electric characteristics of the plasma jet. The process gas is a clean gas or a gas mixture made of two, three or several gases, and is a doping gas. The process is carried out with by impulse current. The gas volume flow rate and/or the gas composition of the process gas are modulated periodically at a frequency of 80 Hz. The temporal periodic modulation is superimposed with an additional temporally periodical modulation at a frequency of up to 8000 Hz. An independent claim is included for a device for plasma keyhole welding of a workpiece using a process gas provided with a gas volume flow rate.