bridgeport

Kasenite, is your friend here... it works and is cheap.

Make sure your anvil is hot, and try welding at a little lower temp. Sometimes too much sparkle indicates too much oxygen getting to your work... get a good reducing fire, bring up to light yellow with just a touch of flux. Hot anvil helps here as does speed and not hitting it too hard for such small work.

I would call it a "Bucket trivet".

Koga, You are blacksmithing.... Forget the hacksaw and cut it on your hardy.

Koga, You have "burned your iron". you will have to grind away all the oxidized parts no matter how deep you have to go... or just throw it away and start fresh. The burned portion is very hard indeed but not in the way you would want it to be.. consider it a "crust" like burned pizza dough. That is the Non technical explanation... This is not carburization, but oxidation.