Who else gets into a total funk when their heat treat numbers turn out low?

Andre Grobler

Well-Known Member
#1
It is not so much that it bothers me that heat treat is a point low, it is that i don’t know what went wrong... and i dont know which way it went, soft due to RA or grain size or some other experimental error...

Well i think i know what went wrong this time, it seems that possibly my thermocouple under reads and i overheated aus temps by about 27 degc... stainless... i am out about 23 at 870... so it may be an easy fix, i test heat treat a known steel at a range of temps... but it grates my ass that 3months ago i dialled in my heat treat very nicely and now it is buggered... i have spent a lot of time the last while doing grain refinement and normalizing in the oven so i racked up a good few hours on my tc... i also feel bummed that there are possibly knives out there that are substandard... i usually err on the side of caution, but of late i have been pushing the envelope a bit to get to use the easy to find steels a bit and now it bit back hard...

How do you deal with the worries?
 

Andre Grobler

Well-Known Member
#2
So i used another thermocouple attached to my multimeter, and it agrees within 3 degrees with the thermocouple in the oven... BUT in the meantime i did not have my usual firebrick sheets on the floor, that on top of my floor elements, just the normal ceramic, the knives were probably radiated by that and overheated, as was the Silver wire I used for checking my temps - so my oven may not actually be out, but my radiation patterns in the oven probably was out... as the blades sat in little holders above the ceramic sheets, while the thermocouple was still shielded from the elements a bit better - perhaps maybe...
 

Andre Grobler

Well-Known Member
#4
It is - i am looking for a hardness tester... and another thermocouple arrangement to clamp at various places along the blade... but there are som many confounding things when measuring temperatures especially high ones, it may just be fairly pointless... but at least then we know
 
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