Pulsed argon arc welding

Pulsed argon arc welding

Pulsed argon arc welding is an argon arc welding in which the welding power source outputs non-uniform current with certain regular changes to the arc, that is, continuous and uninterrupted base current (also known as dimensional arc current) is used to maintain the ionization channel of the main arc, and a pulse arc is generated by periodically applying a pulse current of the same polarity peak value to melt the metal, control the transfer of the droplet, and achieve the purpose of welding.

advantage:

(1) It can accurately control the heat input to the workpiece and the size of the weld pool, improve the resistance to burn through of the weld and the protection of the weld pool, and easily obtain uniform penetration. It is especially suitable for all position welding of thin plates (as thin as 0.1mm) and single-sided welding and double-sided forming.

(2) Each welding point is heated and cooled rapidly, the molten pool metal condenses rapidly during welding, and the high temperature residence time is short, which can reduce the tendency of cracking during welding of thermosensitive materials.

(3) Pulsed arc can obtain greater penetration with lower heat input, so the heat affected zone can be reduced under the same conditions. When welding heat sensitive materials, reducing the passing time of pulse current and the basic current value can reduce the range of heat affected zone to a small value, so that the welding deformation is small, which is particularly important for the welding of thin plates and ultra-thin plates.

(4) To prevent burn through, during thin plate welding or thick plate backing welding, the weldment shall be fully welded with the aid of peak current passing time, and the base current shall be turned to solidify the metal before the molten pool obviously sinks. Moreover, a small current will maintain the arc until the next peak current cycle.

(5) Increase the depth width ratio of the weld, and the penetration width can be increased to 2:1 during stainless steel welding.

(6) Increase the stirring effect of the molten pool. When the average current value is the same, the peak current value of the pulse current is greater than the constant current, so the arc force is large and the stirring effect is strong, which helps to reduce the possibility of pores and non fusion at the bottom of the joint. In low current welding, higher peak current of pulse current enhances arc stiffness and eliminates arc drift.