I just watched a YOUTUBE video on Tig welding steel on the
lincolnelectric channel and I thought I would continue that conversation
with a video of my own.
The welding instructor in the video is Karl Hoes and he did a great job of breaking down the subject of heat input and affects of travel speed on heat input.
I had the pleasure of meeting Karl while on a visit to the Lincoln Electric welding school and so it is no surprise to me that he did such a good job explaining heat input in that video. Thats just the kind of welding instructor he is. Able to explain things in a way that makes sense to students as well as a youtube audience.
As I watched the video, I had some ideas on some things I would like to add in a video of my own... and so that is what I did.
The fact that you are reading this at this very moment tells me you are interested in learning more about welding. Heck, I do too...even after over 36 years in the trade.
I am always looking to learn something...And I did learn a few things while shooting this video.
1. I learned to always check gas lenses. ( had had a defective one and saw some sparks in the film while editing it)
2. travel speed makes more difference than I thought. I knew it was a big player, but I learned in most situations, it makes more difference than voltage or amperage.
3. because I was setting the machine and then going "full pedal" I learned that 80 amps is about the lowest amperage I would ever use to weld 11ga cold rolled steel...but 140 worked great as long as I could keep up with filler rod dips.
4. Pulsing at 200 pulses per second was interesting but that will come in a future video
So here is how this heat input video played out...
I wondered what would happen if I increased amps to 160 and then just ran over the wire so that is exactly what I did next and that weld took 15 seconds and guess what? You guessed it...a narrower heat zone.
Wow. I used twice the amperage than the first weld and wound up with less heat input.
Well heat input is not something to be afraid of. But it is something to figure in to a welding procedure because heat affects different metal in different ways.
So the main takeaway from this video is this...,
Heat affects different metals in different ways.
That is why welding procedures are used for critical welds. A proven weld procedure will help to keep heat input within a range that produces welds with acceptable properties.