clean the saw chain really good before you start. I heated it up good to burn off the oil and when it was cool, soaked it in dilute muriatic acid to strip the scale and grime. When bringing it up to temp for welding, make sure to flux it before it starts to scale, use lots of flux to get in all the little nooks and crannies, there's lots of surfaces to weld up on a chain. You can do it, The only thing you're out if it doesn't work is a bit of chain and some fuel for the forge, and then even you learned something, which is worth more than the fuel and chain
Wow! You MIGHT be able to make things tougher on yourself....but I'm not sure how. Saw chain is about the most difficult thing you could have picked to work with as a newbie. I always try to encourage folks to start with layered damascus.....the chances for success are far greater, the variables way fewer.....and you will learn much more by knowing the materials your working with. Best of luck!