Petriienko O. Influence of Thermal and Electrical Processes on the Modes of Mechanized Gas-Shielded Welding of Steel.

Thesis is devoted to development of a procedure of calculation of the welding process parameters in mechanized gas-shielded welding without short-circuiting, allowing for non-linearity of the thermophysical parameters of the process, and for the heat coming from the drop. The problem of analytical determination has been defined and solved for such main parameters of the welding process as wire feed speed, electrode extension, distance from the nozzle edge to the weld pool, power source voltage, etc., required to ensure a sound welding process. It is shown that the optimum approach consists in assigning the electrode diameter, current, electrode preheating temperatures and drop temperature at the start of calculations, and the extension, feed rate and other process parameters are calculated from the conditions of preservation of the thermal balance and maintained at the required level during welding. It was for the first time calculated, what part of the heat evolved in the contact comes to the wire, and what part of it comes to the welding torch nozzle. The formula for determination of the initial temperature of the wire at its outlet from the current-conducting nozzle was derived for the first time. A program was developed for automated calculation of the parameters of mechanized arc welding, allowing engineering-technological calculations to be quickly performed.