Small Heat Treat Oven

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Brian Rupnow

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This morning I installed the new hinge plates on the oven. The door fits much better with no gaps now. I managed to turn on the Auto-tune function and with the temperature set at 1110 degrees the oven shuts off at 1112 and turns back on at 1108. I'm very happy with that.---and for now, that is all the programming I need. in future I may want to do other things, which may mean that I have to learn more functions, but for now, I'm fine. This essentially ends my work on the oven. Thanks so much for the help you fellows gave me. I would have been lost without some guidance from forum members.---Brian Rupnow
 

dsage

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With respect, one of my main drivers to buy an oven is that I'm not really able to tell temperature by colour. 'Halfway between cherry-red and tomato-red as observed in an old dark and smoky smithy' is way beyond my skills. It is remarkable therefore to see the suggestion to use colours to check the temperature of an oven. The only comparative check I do once in a while is to put a piece of aluminium in the oven and set the temperature just over its melting point. If it then melts I consider the temperature indication to be OK.
It was meant as a verification that the controller is indicating / operating properly. Especially considering Brian arbitrarily inserted the thermocouple himself. When you can confirm the reading then you can rely on it and not use the colours. With respect. The "melting point of aluminum" is probably quite variable depending on alloy and from welding experience is hard to determine by looking at it.
I'm not talking about glowing pieces of metal - yes difficult to tell. Rather the metal surface turns a colour and they are easy to differentiate. There are many colour charts available on the internet. For instance purple and blue are easy to differentiate and the difference in temperature is small.
Again, just as a verification of the oven operation until it can be trusted. If it's accurate at lower temps then it can probably be trusted at higher temps.
If the temperature is important then it is important to be sure your equipment is measuring it accurately. It's not wise to just blindly accept a digital readout.
The temp sticks are a good idea too. But only if you have them at hand.
 
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HennieL

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I managed to turn on the Auto-tune function and with the temperature set at 1110 degrees the oven shuts off at 1112 and turns back on at 1108. I'm very happy with that.---and for now, that is all the programming I need... This essentially ends my work on the oven. Thanks so much for the help you fellows gave me. I would have been lost without some guidance from forum members.---Brian Rupnow
That's good news, Brian - glad I could help a bit :)
Last suggestion - run the auto tune once a year - temperature probes age worse than humans, and it's just good maintenance to adjust for changes...
 

Gordon

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Thanks to Brian's experience I tried to heat treat some parts made from W1 drill rod. In the past I just heated up the part with the torch and quenched it in water. This time I put the part in my kiln at 1450° for one hour and then quenched it and put it in my toaster oven. I just had never even thought about using the kiln. Everything went well except that I screwed up something on my controller setting and had to go back and reset some things.

I am sure that this method is more precise but it certainly is quicker to use the torch.

Gordon
 

HennieL

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Thanks to Brian's experience I tried to heat treat some parts made from W1 drill rod. In the past I just heated up the part with the torch and quenched it in water. This time I put the part in my kiln at 1450° for one hour and then quenched it and put it in my toaster oven.
Congratulations, Gordon - welcome to the club :)
If I may comment on this - W1 only has a very small % of alloying elements, and I would expect that it would only be necessary to soak this steel for a short time - It's never a good thing to keep any steel heated for longer than is necessary, as this contributes significantly to grain growth.
I don't normally work with this steel, but a Google search linked me to the Hudson tool steel corporation that recommends a 30 minute soak per 1" thickness of part.
 

Gordon

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Congratulations, Gordon - welcome to the club :)
If I may comment on this - W1 only has a very small % of alloying elements, and I would expect that it would only be necessary to soak this steel for a short time - It's never a good thing to keep any steel heated for longer than is necessary, as this contributes significantly to grain growth.
I don't normally work with this steel, but a Google search linked me to the Hudson tool steel corporation that recommends a 30 minute soak per 1" thickness of part.
Congratulations, Gordon - welcome to the club :)
If I may comment on this - W1 only has a very small % of alloying elements, and I would expect that it would only be necessary to soak this steel for a short time - It's never a good thing to keep any steel heated for longer than is necessary, as this contributes significantly to grain growth.
I don't normally work with this steel, but a Google search linked me to the Hudson tool steel corporation that recommends a 30 minute soak per 1" thickness of part.
OK thanks. I was not aware that too much time could be a problem. I also found the30 minute time but did not realize that more could be problem. My piece was1" dia x3/4 lg so30 minutes would have been fine. Fortunately the piece is not critical. Just need wear resistance. Next time the parts may be more critical.
 

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