10-30-2018, 07:15 AM
(10-29-2018, 10:52 AM)EOU Wrote: We've been missing your input on this thread from the start Jan! Thank you for jumping in. With brutal honesty, and if we get your drift, we don't think that you put much stock in our Tempilaq experiment. If this is the case, please don't worry about us, we're attempting to learn something here, not propagate a false narrative with flawed experiments. We speculate that your objection might be based in that you don't think that the Tempilaq has sufficient time to react to the very short temperature spikes generated during the grinding process. We do not dispute the validity of this argument but, of course, this assumes that we have framed your thoughts correctly. It does raise a couple of questions though that we hope that you can help us with. (1) Martensitic formations are hard, not soft, aren't they? Please correct us if we've interpreted this incorrectly. (2) An element of Martensitic steel formation is rapid quenching (cooling). Do you feel that natural cooling in room temperature air may constitute "rapid quenching"?
EOU, you are correct!
Ad1) Martensite in steel is extremely hard and brittle, it is full of carbon and stuck dislocations.
Ad2) Martensite is formed during rapid quenching only. Cooling in air is not sufficiently rapid. In my cosiderations what may happen during blade overheating I have mentioned re-arrangement of some iron atoms in martensite only.
To better understand my thought processes please read the attached article by prof. Foell, German material scientist from Uni Kiel.
Jan
MARTENSITE.pdf (Size: 200.63 KB / Downloads: 11)