Question about orb of fusing

Can I turn a 3 socket armor into 3 link by using fusing orb, or will it only create 1 link(even if it takes multiple orbs of fusing)?

It's random.
You could potentially score the full links on the first try.
On high-link items, using an Orb of Fusing could potentially reduce the number of links.

It is possible to get all the sockets linked together, but it will take multiple orbs of fusing to achieve that.

thanks guys

The more sockets you try to link, the less the chance you have of linking all the sockets. I.e. 3 socket is WAY easier to link than linking 6 sockets. You could probably link a 3 socket with a handful of fusings, but honestly linking only 3 sockets isn't worth it unless it's a really good item.

You might want to throw a few jeweler's at it for 4 sockets (assuming it can get 4 sockets), then chrome it and finally fuse it.