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pyrometer question
- Thread starter Astygma
- Start date
- Joined
- Jul 2, 2000
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- 1,494
In the absence of pyrometer, I'd be more apt to use color and magnetism as indicators of temperature.
In regards to quenching temp (this quote is taken from here):
"...The point at which the steel becomes Austenite is very important. Several things happen at this stage. I know you've all seen what's referred to as the shadow in hot steel. Well, that shadow is the dividing line between the Austenite or Gamma structure (higher temp) of the steel and the Alpha structure (lower temp) of the steel. So, as the steel heats up, the shadow moves through the steel from the higher temp area toward the low temp area or from the end of the bar/blade towards the handle. (Scratching my head here, how to get the point across?)
This shadow is your visual cue that you need to check with the magnet. So, when you see the shadow in the steel as you're heating it up, start checking it with the magnet for critical temp in the steel. In the completely forged blade, the shadow will travel up from the edge toward the spine. From the thinner to thicker sections of the blade. It will follow any curves in your blade as well. Pay close attention the next time you're heating up a finished blade and you'll see what I mean. Don't get it too hot and then wait for the magnet test to work because it won't work on the way back down. I can't stress this point enough. If you get the steel too hot it will cause grain growth and you'll have to stop and normalize the steel in order to get this under control. "
There are "temperature cones" will give you an idea ( I'm not sure of their accuracy) of what temperature you are at.
Regards,
Greg
In regards to quenching temp (this quote is taken from here):
"...The point at which the steel becomes Austenite is very important. Several things happen at this stage. I know you've all seen what's referred to as the shadow in hot steel. Well, that shadow is the dividing line between the Austenite or Gamma structure (higher temp) of the steel and the Alpha structure (lower temp) of the steel. So, as the steel heats up, the shadow moves through the steel from the higher temp area toward the low temp area or from the end of the bar/blade towards the handle. (Scratching my head here, how to get the point across?)
This shadow is your visual cue that you need to check with the magnet. So, when you see the shadow in the steel as you're heating it up, start checking it with the magnet for critical temp in the steel. In the completely forged blade, the shadow will travel up from the edge toward the spine. From the thinner to thicker sections of the blade. It will follow any curves in your blade as well. Pay close attention the next time you're heating up a finished blade and you'll see what I mean. Don't get it too hot and then wait for the magnet test to work because it won't work on the way back down. I can't stress this point enough. If you get the steel too hot it will cause grain growth and you'll have to stop and normalize the steel in order to get this under control. "
There are "temperature cones" will give you an idea ( I'm not sure of their accuracy) of what temperature you are at.
Regards,
Greg
Cougar Allen
Buccaneer (ret.)
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- Oct 9, 1998
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- 76,565
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- Nov 16, 2005
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Hey Jeremy I am somewhat of a novice here but I read somewhere about color changes to determine heat. I am in Kent.
-Mike
-Mike
- Joined
- Jan 24, 2001
- Messages
- 501
Jeremy you can look at colors or whatever for a long time and likely get competent with experience. I find it a lot easier to use a thermocouple and know for sure what the heat is. All depends on how deep you want to get into it and how accurate a temp you need or want.
There are quite a few bladesmiths in western WA. I'm in Tenino
There are quite a few bladesmiths in western WA. I'm in Tenino
- Joined
- Jun 20, 2003
- Messages
- 65
You can pick up a digital thermometer with a Type K thermocouple at Harbor Freight for around $40. The thermocouple is not the best quality but it will get you started. The start looking on ebay and you can pick up " real " ones for as little as $10.
I was very suprised how off I was with my color / temp guestaments. I very much like now KNOWING I am soaking my O1 at 1500 degrees or 1095 at 1425 instead of hoping. I have more confidence in my work now.
Seth
I was very suprised how off I was with my color / temp guestaments. I very much like now KNOWING I am soaking my O1 at 1500 degrees or 1095 at 1425 instead of hoping. I have more confidence in my work now.
Seth