Polished welding wire versus copper-plated welding wire. Which is better? Which to choose?

History of welding wire for welding semiautomatic devices in Ukraine. Starting from the 1960s, welding wire began to be actively used instead of welding electrodes. The first welding wire for semi-automatic machines was not copper-plated and was supplied in large coils the size of a car wheel weighing 80-100 kg.

There was a large residue of black technological grease on the wire, which is why the wire was even called "black". Residues of technological lubricant negatively affected the welding process, contaminating and clogging the bowden (cable - guide channel) and the current collector tip. Contamination of the bowden led at the beginning to difficult wire feed into the welding zone, and later even to a complete stop of the feed due to a bowden clogged with grease.

Contamination of the current collector tip resulted in poor welding contact, intermittent feeding, and the wire getting stuck in the tip with a complete stop of welding. The rest of the technological lubricant was regulated by GOST 2246, where paragraph 3.28 states “On the surface of non-copper-plated welding wire, traces of soapy lubricant weighing up to 0.05% of the mass of the wire are allowed.” - this meant that on 1 ton of welding wire there could be no more than 500 grams of soap grease. And in paragraph 3.27 it is written that “Technological lubricants are not allowed on the surface of low-carbon and alloyed wire, with the exception of traces of soap grease without graphite and sulfur.”

But in fact, it was almost impossible to check and determine the composition of the rest of the technological lubricant, because everything was mixed there. The black color was due to the fact that the soap grease burned out and turned black due to the high temperature of the drawing. It was obvious that there was a need to clean the surface of the wire from the remnants of technological lubricant and improve the contact between the wire and the current collector tip. In the search for a solution, specialists and scientists from the welding and steel wire directions united and an idea was developed to clean the surface of the wire, as well as additionally apply a copper coating to the wire surface to improve contact during welding.

Specialists and scientists have considered that since copper is a good conductor of electric current, the copper coating on the welding wire should, in theory, improve contact during welding. This is how the copper-plated welding wire appeared, and yes, if you compare it with the previous black non-copper-plated welding wire, then of course it was many times better - the bowden (cable) and the current-collecting tip were not clogged with grease. Copper-plated welding wire begins to gain popularity approximately from 1995 and has become mass until now. But no matter how good the copper-plated welding wire is, even from eminent manufacturers from Sweden, America, Turkey, Korea, Ukraine and China, all welders are faced with the fact that if you start welding on a new current collector tip, then at the beginning the welding goes well, but when using approximately 15-25 kg of welding wire, in the hand of the welder of which he works, twitches will be felt that are transmitted from the welding torch in which the wire passes.

It has been experimentally established that if you stop welding, unscrew the current-collecting tip and clean it or replace it with a new one and resume welding, then the twitching coming from the burner will disappear for a while, but will again appear after using 15-25 kg of wire. If you do not clean or replace the current collector tip with a new one, then the twitching coming from the welding torch during the welding process will intensify and eventually welding of the welding wire inside the current collector tip may occur and the welding process will be interrupted. We decided to figure out what would contaminate the current-collecting tip inside, because there are visually no significant residues of technological lubricant on the surface of the copper-plated welding wire.

If you clean the collector tip over a white, clean piece of paper onto which dirt will fall, you will see that solid pieces and copper-colored flakes fall out of the collector tip during cleaning. We made a chemical analysis of the spilled pieces and flakes and it was confirmed that these were pieces and flakes of pure copper.

Where does copper come from and accumulate in the current collector tip? The answer is from the copper coating of the welding wire. We have done a lot of experiments and observations and found that due to the high temperature during welding, the copper coating peels off and peels off the surface of the wire and welds in small pieces inside the current collector tip - where the welding wire passes. The process of accumulation of copper inside a new or cleaned current collector tip occurs gradually, therefore, at the beginning of welding, when there is no burnt copper inside the current collector tip, welding goes well, and when burnt copper begins to accumulate inside the current collector tip, it mechanically impedes the passage of the wire insidethree current-collecting tips and impair contact.

That is why the welder, after penetration of 15-25 kg of copper-plated welding wire, begins to feel twitches coming from the welding torch. It became clear that the highest quality welding wire should not only be cleaned of process grease after drawing, but also not have a coating on the surface that could burn and accumulate inside the current collector tip. Also, the welding wire should pass without hindrance inside the current collector tip with minimal friction and ensure the best possible electrical contact in the current collector tip.

This is how polished welding wire was produced. Polished welding wire is a steel wire that has been de-greased after drawing without metal coating, the surface of which is polished in a special assembly to obtain the best possible contact and the best possible glide in the current collector tip. The chemical composition, mechanical properties of polished and copper-plated welding wire are the same, the difference is only in the surface.

Having carried out numerous technological tests both on our own welding equipment and with many consumers, we can state with full confidence that polished welding wire surpasses copper-plated welding wire in terms of welding and technological properties. The most important advantage lies in the fact that during welding, the current collector tip does not accumulate metal deposits in itself, which later serves as an obstacle to the passage of the welding wire and worsens the contact in the current collector tip.

Respectfully yours, Director Alexey Korolev.