I'd be OK with any use...
You can buy a welded ball assembly from Harbor Freight, and it's welded in China with sub-standard components, using sub-standard equipment... Your welds look solid, and from a materials standpoint, there really isn't any issue with what you've done.
I take that back. Generally speaking, you need to grind off the chrome plating before you weld, I believe. But you welded the top and bottom, so it's probably 2x stronger than the crappy HF 3-way ball mount, and I HIGHLY doubt they grind the chrome off the balls before they weld them.
Nice looking welds, btw.