That might not have been corrosion. I had a white residue on the threads, which was the thread lock. I was unable to remove the first two bolts, so I just used a paint stripper on its low setting in 3 bursts of a few minutes with an hour or so in between (to cool) and they reluctantly gave up. Use good long handle Allen keys. I use the T-bar type, using the short end in the head and the long shaft in hand for leverage. The wheel was off the bike and flat on the floor, held by my feet!