Question about tempered steel and temp.

ron_m80

ron_m80

Tempered Member
Joined
Mar 1, 2009
Messages
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I was wondering if any of you good people would mind telling me, because YOU KNOW FOR CERTAIN, what the danger temperature for "de-Tempering" a 1095 carbon steel machete at approx. 57c would be?

Thank you in advance.
 
But it's a reliable indicator of going too far! I really do KNOW THAT FOR CERTAIN :) A bit of yellow or bronze color doesn't seem to hurt much, but you're right, purple/blue means... "hmmm this machete is going to get a lot smaller before it will hold an edge again". Don't ask me how I know. :o

Are you looking to re-grind a finished blade? Just work bare-handed and cool often and thoroughly. No heat-color at all is probably best.

Sorry for the smart-alec initial response... someone who actually knows what they're talking about will be along shortly to help you with the actual temperatures you're looking for. How are you going to measure the temp while working on the blade?
 
ron_m80 said:
I was wondering if any of you good people would mind telling me, because YOU KNOW FOR CERTAIN, what the danger temperature for "de-Tempering" a 1095 carbon steel machete at approx. 57c would be?

Thank you in advance.
Click to expand...

None of us can really tell you for sure unless we know:

  1. How many times you normalized, and at what temperatures, and with what soak times
  2. What temperature you quenched from
  3. Your soak time before quench
  4. What quench medium you used
  5. The temperature of said quench medium

Then a guy could give you a decent guess. The problem is that all of these things affect the amount of carbon that goes into solution, gets locked into the iron matrix, converts to martensite, and thus creates the "as quenched" hardness. From that point, you temper back to relax some carbon out of the iron matrix, convert retained austenite to martensite, and temper a second time to bring the hardness back down on the freshly converted martensite.

So, if you need answers that are for certain, these variables need to be controlled. Furthermore, you need to start with the recipes from industry for 1095, based on the TTT charts, and verify the results of your work, in your shop, with your equipment, with a hardness tester and adjust as necessary to get where you want to be.

I know that's probably not the answer you were looking for, but you seemed very concerned with getting it right, and that's the beginning of how you do that...

-d
 
deker said:
I know that's probably not the answer you were looking for, but you seemed very concerned with getting it right, and that's the beginning of how you do that...

-d
Click to expand...

No that answer is fine, its a good thing to be put in your place when you ask a professional how to hack your way into his craft.

But to be honest, I wasn't looking to get too specific. I just wanted to avoid any unecessary chatter, (thought i soon forgot the title of the forum i posted to, i was acting like i posted it in general discussion, for the lack of concideration i appologize ).

I have sucessfully ground blades before without destroying them, I can keep it workable, I had a passing thought to use heat indicating paste to keep the steel temp monitored while working. Only to read that washes off with water, not a good thing since I would likely be using it to control the steel temp. ;)

Thanks for the replies gentlemen.
 
ron_m80 said:
No that answer is fine, its a good thing to be put in your place when you ask a professional how to hack your way into his craft.
Click to expand...

Oh, please don't go thinking I'm a professional! :) I'm just a hobbyist steel hack.

I also re-read your post and must confess to slightly misunderstanding your original intent. So, I'll give you the much simpler answer that make this easy...that is: "Hold it with bare hands while you grind". Generally, if you can still hold onto it, you're safe. Additionally, if you see any color come up in grinding, cool the blade quickly in water and go back to grinding more gently, or with a fresh, sharp belt.

Take care,

-d
 
No problem guys, I have thicker skin than that. But your names are high-lighted orange indicating this is your forum. ;)

I will be working with the blade bare-handed and keeping it cool. (working that way would kinda require cool steel)

Maybe i'll get brave enough to post a pic of it later.
 
Ron Dunk it at warm not hot. Apass or 2 and dunk,you can't get it too cool but you sure can get it too hot.
Stan
 
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