(12-22-2017, 11:51 AM)me2 Wrote: One final thought on the grinding heat topic. A fair amount of research has been done into how much heat is generated while grinding. The most reliable study I've read shows a temperature of somewhere near 1000 F generated during grinding. Some other first hand conversations indicate the temperature can (not is or will be, but can) be much higher. I know GE regularly does tests to see if grinding their parts has resulted in excess grain growth in nickel alloys meant for high temperature applications.
German steel expert R.Landes considers as proven that the peak grinding temperatures may be for some small fraction of a second as high as 2000°C.
Some five years ago I have read about technology called grind-hardening, which utilises grinding heat to harden the workpiece surface. During this short-time HT process the martensitic hardening is achieved by self-quenching mechanism.
It is easy to imagine that when the heat generation in the contact zone between grinding wheel/belt and the blade is not sufficient for surface grind-hardening, it may be sufficient for tempering.
Jan