Dusty is one step ahead of me. The heat could be from friction turning but could also be from grinding which should be of no consequence. If you get the same result through the rpm range (start low, progress to high) then I'd start suspecting the HSS. But that's a stretch. Pretty sure that's the country of origin of my KBC T-blades. If anything should cut fine after sharpening & just degrade quicker. Try aluminum (with fluid). A sharp blade should make a nice long continuous chip as you manually apply in feed.