If you read my recent blog on heat balance, you know that there are five different techniques that can be used to balance weld heat that don’t involve making changes to materials or part design. And at the end of the blog I mentioned that if you’re still having difficulty after trying all five of the techniques, you may want to consider adding projections to one of the parts.
Equipment calibration may not be the most exciting activity, but it can go a very long way in saving you both time and money by reducing plant down-time due to process control fluctuations.
All right folks. Let’s cut to the chase. Successful resistance welding boils down to heat balance: getting both parts up to their bonding temperature at the same time. If too much heat goes into one part, and not enough into the other, the overheated part can become weak, and the weld won’t be strong.
What’s the fastest and easiest way to improve your manufacturing welding processes? That’s simple: use a closed-loop resistance welding power supply! And you’re thinking “okaaay…what’s ‘closed-loop’ and why do I want to use it? I know why you want to sell it – it’s a higher end power supply that costs more money, but exactly how will that help me in my process?” Well, I’m going to tell you.
What is closed loop? At a high level, closed-loop resistance welding power supplies use current and voltage feedback sensors to precisely control the energy delivered to the parts. This ability to accurately control weld energy is a key factor in overcoming problems associated with process variation and the rapid changes in resistance that happen during the weld.
Our lab gets a lot of calls asking us how to use resistance welding equipment safely, so I thought I would put down a few words on the most common issues affecting safety.
Just a few posts ago, I shared some information on online and mobile apps that help take the guesswork out of material weldability. Since that post, I’ve gotten some feedback that leads me to believe a lot of people would like a bit more on the basic questions of “what electrodes should I use for spot welding?” and “can I spot weld (material A) to (material B)?”
When it comes to resistance spot welding problems, I think I can say I have literally seen them all. I've been in the troubleshooting trenches for years and have worked to overcome weak welds, metal expulsion, and electrode sticking, as well as discoloration and sparking (there are many more!)