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Let's analyze one difficult question for a beginner, but how to properly set the welding current? After all, distinguishing slag from metal and correctly adjusting the current is the basis of the basics, without it it will not be possible to go further.
Yes, there are such tables of ratios of parameters of metal thickness, electrode diameter and welding current. But you should be very careful to focus on them.
Indeed, in modern welding inverters from different manufacturers, this current scale is also very conditional. On different machines, you can set the same current, but in fact, when welding, it will be a very different current. But what to do and what to do, especially when the experience is minimal? There is one way that gives greater accuracy in the correct selection of the current.
But I will say right away that for this method you need to take electrodes for welding so that their diameter matches the thickness of the metal. And it is better to always have electrodes of different diameters in stock. You do not need to weld everything in a three.
If the metal is 1.5 mm thick, we take the electrode with a diameter of 2 mm.
metal 2 mm - electrodes 2.5 mm
metal 3 mm and more - electrodes 3 mm
When we light the electrode and start to weld the metal, we see the formation of a weld pool. A welded bath is a lake of molten metal under the tip of a burning electrode. And so on the bath, you can quite accurately set the current, even without looking at the spinner of your inverter with the values \ u200b \ u200bof values.
The weld pool will have different widths, depending on what current we set. We add current, and the weld pool gets more energy, the metal melts more, the pool of molten metal spreads wider. And according to this spread of the weld pool, the current can be adjusted correctly. See how.
We take an electrode of a suitable diameter for the specific thickness of the metal that we have to weld. You should first take an unnecessary training piece of iron to adjust the current.
We light the electrode and slowly lead it without hesitation keeping a short arc. And we look at what width the weld pool will spread out. We have to choose a certain width of the spreading relative to the diameter of the electrode without coating.
We weld a seam on the training piece of iron and beat off the slag. The width of this seam, with the correct selection of the current, should be from 2 to 3 electrode diameters. But, here's another thing
The spread of the seam relative to the diameter by 2 times is the minimum welding current for this metal thickness, it is suitable for welding butt seams in the lower, overhead and vertical position. But this is the very minimum, from this ratio of diameter and width it is quite possible to add a little current.
But the spread of the seam is 3 times the diameter of the electrode - this is the maximum. Such a current is suitable for welding tee and fillet welds, where more current is needed than other joints. But usually 3 diameters is even a lot, and we slightly reduce the current.
No one will say the exact values, which is why we are considering certain ranges. And this will just be the range from 2 to 3 electrode diameters, this is the minimum and maximum, normal welding will go just within this range.
Simply with such a selection of the current so that the width of the weld spread is from 2 to 3 electrode diameters, the following processes will take place.
This energy will properly heat the metal, which is why the weld seam will be formed as needed, correctly. Plus, this pressure of the welding arc will not allow the slag to fill the weld pool.
Friends, we do these settings initially without looking at the adjustment scale on your device. And when we select these ranges for various thicknesses and diameters of electrodes, then we will already know these necessary values on our device and the next time we can set the current on our inverter.