how much heat to destroy heat treat?

R

rsco

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May 9, 2009
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I was wondering how much or how little heat it takes to destroy the heat treatment on infi? This would include forms of sharpening, polishing and anything else you can think of. It's a long shot but can anyone guess temperatures, even if compared to the temps used to heat treat knives in general? Thanks!
 
A post I read quite a while back said something to the effect of 800+ degrees.
 
Would 800 degreese refer to the heat treatment of infi? Or the temperature a finished infi blade would have to reach such that the user effectively nulls some of the favorable qualities of the factory busse heat treat?
 
i've had mine to hell and back with no damage at all :thumbup:





hell = hades, you know, bible talk


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a lot of finishes such as gun-kote are baked on @ 300+ degrees and i know of a few that bake at 400 so we know that won't hurt heat treat much if at all. micarta will not go past 300 without sweating resin and warping.



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idahoskunk said:
a lot of finishes such as gun-kote are baked on @ 300+ degrees and i know of a few that bake at 400 so we know that won't hurt heat treat much if at all. micarta will not go past 300 without sweating resin and warping.



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Skunk is on the money here! This is why in the turbine industry we are using G-11 now instead of G-10 or Micarta. The thermal properties are much better for extended heat exposure. The max heat for running is around 329'F depending on a few details and spec of what supplier your talking about. But as a general rule it's in the ball park.
 
So what all that means is the scales will melt off before you hurt the heat treatment. :D
 
If you are worried about power sharpening with a belt sander, that can damage the heat treat very quickly, because the edge is so thin that heat builds up very quickly.
 
idahoskunk said:
a lot of finishes such as gun-kote are baked on @ 300+ degrees and i know of a few that bake at 400 so we know that won't hurt heat treat much if at all. micarta will not go past 300 without sweating resin and warping.



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IonBond "DiamondBlack" DLC coating is baked on at 425 degrees, and does not affect the heat treat at all. :thumbup:
 
Most heat treated blade steels start being affected at about 400 degrees. 800 seems REALLY high to hold the heat treatment without any affect.
 
We really need to add this question to the FAQ sticky.

on_the_edge said:
I ***think*** somebody has mentioned that it would take about 900 F to damage the temper of INFI. A dishwasher and inside a car is not going to be even close. Micarta is also very resiliant.
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Quoth Jerry in this post: http://www.bladeforums.com/forums/sh...42&postcount=2

As for INFI and temperature extremes, it is amazing. INFI is tempered at nearly 950 degrees. It does not begin to lose any significant hardness until it is held above 1050 degrees for a considerable amount of time. I have to believe that it would need to be extremely mishandled in order to do any noticeable damage.

Most of the simpler high carbon steels (of which INFI is NOT a member) can be drawn down in temper in a matter of seconds if the temperature hits above 500 - 800 degrees.
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Skunk killed micarta in the oven, but that was somewhere in the 250 degree range, I think.
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Nuke41 said:
Most heat treated blade steels start being affected at about 400 degrees. 800 seems REALLY high to hold the heat treatment without any affect.
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True for most simple carbon steels and some alloy steels. Most high end cutlery stainless steels however such as ATS34, 154CM, the CPM sXXv series, and high speed steels have tempering specs well over 400 degrees, some over 1000 degrees (and still resulting in a RC 60+ product). Some even get harder as you go up the temperature range. If S90V is tempered at 750, a lower temper afterwards will not affect the blade negatively. You can even go up to 1050 on the temper for best stress relief, but you give up some corrosion resistance.

All cutlery grade stainless steels need to avoid the 800-1000 range when tempered, as this will cause embrittlement. IIRC simple carbon steels have a similar problem around 600-700 degrees. What range to avoid due to embrittlement is something only jerry knows, but it's probably hotter than your home oven can get.


rsco said:
I was wondering how much or how little heat it takes to destroy the heat treatment on infi? This would include forms of sharpening, polishing and anything else you can think of. It's a long shot but can anyone guess temperatures, even if compared to the temps used to heat treat knives in general? Thanks!
Click to expand...

When sharpening on power equipment you gotta be careful, because it's easy to hit 2000 F at the very edge if you let the blade linger in one spot too long.
 
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