03-13-2018, 10:03 AM
Upon further reflection, I don't know of any mechanism aside from grinding heat that would soften steel during grinding. However, I have seen thin foil like burrs on edges ground on slow moving water cooled wheels. These types of burrs behave exactly like the ones Grepper describes. They flop around and behave very differently from the way we expect hardened steel to behave. However, when brittle materials get very thin, they begin to behave oddly. Even hardened steel has 2 to 3 percent ductility, and in foil like sections, this can be enough to explain their behavior.