THE RESEARCH OF TEMPERATURE DEVIATIONS IN WELDING PROCESS DURING THE DISTURBING ACTIONS

The authors offered the methods for determining temperature in the welding zone, taking into account the influence of various disturbances. Basing on these methods, the surface temperature of the heat-resistant steel plates welded by double argon-arc welding without cutting edges is calculated. The authors calculated the thermal cycle of selected point on the outer surface of a part at the distance y = 0,6 cm from the axis of the heating source and obtained the point with the maximum temperature (x = 0.7 cm), for which the influence of permitted deviations in the nominal values ​​of welding conditions (thermal diffusivity, plate thickness) and welding modes (effective power and welding speed) are determined The article gives the values ​​of relation coefficient of disturbance transmission (RCDT). It is the controlled parameter reaction for the change in controlling parameter in relative units in the absence of controlling system. It was found that while controlling the point temperature, the relative influence of welding speed exceeds the influence of effective power while in case of regulation of direct weld penetration there is almost no difference. It is advisable to use the welding speed as the controlling parameter since it does not influence the arc power and does not react in the "power source - arc - welding pool" system. According to the proposed method, the study of temperature change of a point with the coordinate at which the maximum penetration takes place (y = 0.6 cm, x = 1.1 cm) and a point with y = 0,8 cm, х = 1.1 cm. On the basis of the results comparative analysis, to regulate the welding process, it is preferable to select a point with maximum weld penetration as the penetration and temperature deviations at a given point coincide in time.