turning tools went dull quick

[woodbutcher]

I wish I owned some Sorby chisels and could report 1st hand. They have a top notch reputation and mine are inferior yet I get about 15 plugs with mine before resharpening is necessary. This wasn't always the case. I had an experience similar to yours. I failed to complete all tooling on the workpiece prior to sanding. I figured that abrasive particles were being transfered from the sandpaper and becoming embedded in the wood. 2 or 3 plugs and the tools were rendered childsafe. Nowdays, once I touch the wood with sandpaper, the plug never sees steel again.
If just 1 tool was going dull on you I'd say i'ts possible that it was improperly tempered, but all 3? what are the chances? Guess stranger things have happened. I'm fresh out of ideas maybe others can help.
Good luck, keep at it.