First of all, the hand should be steady, that is, the hand should have the power to control the welding torch.

Breathe carefully. When breathing, the chest will expand and contract, which will drive the arm to move and make the welding unstable. Practice breathing, keep your fingers in a certain posture, breathe carefully, control your hands or fingers in a straight line with your will, and find the feeling of breathing.

A rhythmic swing. When swinging, you should stay at the break point for 0.5 seconds, and the straight line segment should be fast. When exercising the sense of rhythm, you can shout slogans at 12- 12- 12, and control the rhythm according to the slogans.

2 Key points of secondary welding operation

Joints with grooves in vertical or inclined positions must be welded from bottom to top, and butt welding and vertical fillet welding of thin plates without grooves can adopt downward welding; Horizontal, horizontal and vertical butt joints can be welded to the left.

Outdoor work, when the wind speed is greater than 1m/s, windproof measures should be taken.

Reasonable welding sequence must be selected according to the structure of the workpiece to be welded.

Both ends of butt joint should be equipped with arc striking and arc extinguishing plates with appropriate size.

Be sure to clean the dirt in the hose and the splash from the nozzle.

For plate joints with grooves, especially thick plate multi-pass welding, the welding wire should stay on both sides of the groove for a short time when swinging, and the thickness of each layer of sawtooth strip should not be greater than 4mm, so as to make the weld fusion good.

3 adjustment skills of current and voltage in double shielded welding

Welding current is the main factor affecting the quality and productivity of welded joints. Excessive current, rapid metal melting, deep penetration, large metal splash, and easy to produce defects such as burning through and undercut. If the current is too small, it is easy to produce defects such as incomplete penetration and slag inclusion, and the productivity is low.

When determining welding current, covered electrode diameter, weldment thickness, joint type, welding position and other factors should be considered, among which covered electrode diameter is the main factor. Generally speaking, small current is selected for fine covered electrode and large current is selected for coarse covered electrode.

During vertical welding, horizontal welding and overhead welding, the welding current is less than that of flat welding 10% ~ 20%. Stainless steel covered electrode and alloy steel covered electrode have high resistance and thermal expansion coefficient. When the welding current is high, the covered electrode coating will fall off due to redness, which will affect the welding quality. When welding, the welding current should be reduced accordingly.