Your location ： Home > News > Industry information

Knowledge of welding technology
Publisher: suzhou kailinneng automation equipment co., LTD Release time：2023-03-23 15:03:38 Click on the number of times：75 Shut down
1. What is arc initiation? What are the methods of starting the arc? What should we pay attention to when starting the arc?
The process of igniting and producing a stable arc is called arc initiation. Arc starting method scratching arc starting method and direct arc starting method two.
Scratch arc method, the end of the electrode is aligned with the arc, and then like a match, so that the electrode in the welding surface using wrist gently scratch, scratch distance 10-20 mm, and lift the electrode 3-3 mm.
Direct arc ignition method, first align the electrode with the welding part to be welded gently touch, and the electrode timely lift 2-3 mm, can ignite.
When starting the arc, the welding rod should be lifted quickly, otherwise it is easy to stick to the workpiece. If sticking occurs, the electrode can be shaken left and right after opening, if not open, to loosen the welding pliers, cut off the welding circuit, to be slightly cold after processing.
The following points should be noted when starting the arc:
(1) The arc length shall not exceed the diameter of the electrode after starting the arc. Do not use too much force when starting the arc, to prevent the end of the drug skin crack, or even fall off, affect the arc and welding.
(2) when starting the arc can not be at random on the welding, especially high strength steel, low temperature steel, stainless steel. This is because the arc scratch site is easy to cause hardening or micro-cracking, stainless steel will reduce corrosion resistance.
(3) when starting the arc, if the electrode and the weldment are connected together, it can not be taken off by shaking, and the welding pliers should be taken off immediately. After the electrode is cooled, it is easy to take off.
2, what is the point fixation before welding?
In order to fix the relative position of the two welds, positioning welding (often referred to as pinching) is performed at both ends of the workpiece before welding.
Clean up the slag after setting. If the solder is longer, it can be fixed every 200-300mm or so.
3. What is direct connection? What is a reverse connection?
In the welding process, the two poles of the arc welder are respectively connected to the electrode and the weldment, forming a complete welding circuit.
For a DC welder, one is extremely positive and the other extremely negative. When the weldment is connected to the positive electrode, the welding electrode (electrode) is connected to the negative electrode, which is called positive connection (referred to as positive connection), and vice versa (referred to as reverse connection).
For AC welders, because the polarity of the power supply is alternating, there is no problem of positive and reverse connection.






4. How to start the electrode arc welding?
The beginning of the weld is the beginning of the weld, due to the low temperature of the welding parts, after the arc can not quickly make the temperature of the welding parts, under normal circumstances, this part of the weld residual height is slightly higher, deeper penetration is shallow, and even bad fusion and slag inclusion, so after the arc should be slightly elongated arc to preheat the workpiece, and then the pressure arc for normal welding.
Flat welding and alkaline electrode adopts back welding method, starting arc 10 mm from the distance of the starting spot, back welding to the starting point, gradually lowering the arc, while the electrode does slightly swing, so as to achieve the required width of the weld, and then normal welding.
5. What is the welding arc voltage? What does it do?
The voltage drop between the two ends of the arc (the two electrodes) is called the arc voltage. It includes cathode voltage drop, anode voltage drop and arc column voltage drop, and is numerically equal to the sum of the three voltage drops.
Arc voltage mainly depends on arc length, long arc voltage is large, short arc voltage is small. If the arc voltage is large, the weld width is wide, and if the arc voltage is small, the weld width is small.
In the welding process, the arc voltage should be increased with the increase of welding current in order to obtain the appropriate width and depth.
6. What is the welding speed? What does it do?
The length of single weld completed in unit time is called welding speed. The speed of welding depends on the welding current. The welding current is large, can improve the welding speed, but do not mistake the welding production efficiency depends on the welding speed;
It is not the higher the welding speed, the higher the welding production efficiency, but the welding current size determines the level of welding production efficiency. The larger the welding current, the more molten metal per unit time, the higher the welding production efficiency
Under certain welding current, the welding speed affects the thickness of weld passage. If the welding speed is large, the welding pass is thin, and if the welding speed is small, the welding pass is thick.