this is what i'm thinking, it's the "Bond" of the abrasive that's too strong, i.e. not letting the wheel break down as you are describing. as it breaks down it keeps it sharp. if the bond of the abrasive is too strong, it doesn't release the grains as they are used, and hence clogs up or heats up. A softer bond does provide certain advantages — it sheds its grains more rapidly to provide a faster cut. With a stronger bond, the bond may hold the grains in place after they have become worn. A softer bond releases them faster to reveal fresh, sharp grains more often and increase the wheel's cut rate.

the abrasive type seems to be correct, aluminum oxide. but i dont' see the bond listed. you'll need a technical spec for that

i'd suggest simply trying a different brand of cutoff wheel, and look to see if there is something in the spec about the bond.

stainless is another animal, and this wheel states it specifically. i'd try something different.

hope i've helped a little