Compared with ordinary argon arc welding, the characteristics of pulse argon arc welding are as follows: 3.1. It can accurately control the heat input to the workpiece and the size of the molten pool, improve the ability of weld penetration resistance and maintaining the molten pool, and obtain uniform penetration. By adjusting the size of the base current IA (as shown in the figure, also known as the dimensional arc current), the size of the pulse current IB and the pulse frequency, that is, the base current duration TB

And the reciprocal of the sum of pulse current duration TA. The input and distribution of welding heat energy can be controlled, and the size of the molten pool can be controlled to obtain a molten pool as small as possible. At this time, the molten pool metal will not fall due to gravity at any position, which is difficult to achieve in general arc welding.0 ﹤ DC pulsed argon arc welding current waveform ﹤ IB ﹤ IA I t   |- ta -|- tb -|

Compared with traditional manual and semi-automatic welding, what are the characteristics of pipeline automatic welding machine advertisement

Using automatic welding machine for pipeline welding, the skill requirements for welders are lower than manual welding or semi-automatic welding, but their training is still essential. In addition, although there are obvious differences between automatic welding and manual welding or semi-automatic welding, manual welding each welding spot is heated and cooled rapidly. Because the weld formed by pulse arc is formed by overlapping welding spots, the instantaneous impact force of pulse arc is strong, which has a strong stirring effect on the spot weld pool, which is conducive to the escape of impurities and gases. In addition, the metal in the weld pool condenses quickly and the high-temperature residence time is short, so the weld metal structure is dense and the tendency of hot cracks is greatly reduced. Especially in stainless steel welding, the welding principle is small current, narrow weld and fast straight-line welding. If the welding line energy is too large, the alloy elements will be burned seriously (i.e. the formation of chromium carbide. If the chromium content is less than 12%, the material will rust), and the tendency of intergranular corrosion will be intensified. The maximum control can be achieved by DC pulse argon arc welding.

pulse arc can obtain large penetration with low heat input, which is different from the constant current used in ordinary argon arc welding. Instead, using pulse current can reduce the average value of welding current and obtain lower line energy. Therefore, the heat affected zone and welding deformation can be reduced under the same conditions