1084 Heat Treat

L

Living The Dream

Joined
Feb 20, 2016
Messages
158
I have looked through the stickies and got some tidbits. Still a little bit confused though.

I have a couple of blades cut out and drilled. They are aldo 1084.

I have two gallons of canola ready. I have a commercial forge ( majestic).

It should be simple. ha ha

1. heat to cherry red and then dip in the canola while moving it around. Oil heated to about 120 with a railroad spike.

2. let blades cool to room temp

3. temper in an oven twice at 400 allowing to cool to room temp

Is that about right give or take?

Also what is the soak allude to? What is that? One thread said soak for 5 minutes. soak in what. It seems that is a term that I do not know what it means.

Any help or advice would be appreciated.
 
Welcome to Bladeforums. 1084 is the easiest of the carbon steels to heat treat, even with a forge.

Without going into the metallurgy of it all, I can offer some pointers for you. The carbon steels Aldo carries are excellent, but they come in a very soft structure for easy machining, but this poses some problems in heat treating. To overcome some of those problems, it is best to normalize 1084, then harden it. I'll try to keep it simple for you.

With your forge as a heat treat set up, you'll need to have a magnet handy. The magnet will stop sticking at around 1414-1425 or so, but you need to be AT 1500 to quench. If you want to try to harden it without normalizing, then I would do this.....get your forge up to heat. Place the blade in. The magnet will not stick once the blade is 1414 or so, but you NEED to be at 1500, this means a shade or two more red past the non magnetic point. You'll have to do that part by eyeball, best in low light conditions. An actual soak isn't really needed to harden 1084, but it does not hurt, especially with Aldos vanadium 1084. What we mean by soak is simply hold the steel at a given temp for a given amount of time. In a forge, this is done by pumping the blade in and out of the heat source. Careful don't overheat thin parts like the tip. Once the blade has reached 1500, and again best to hold it there for a few minutes, quench in a few gallons of canola oil that has been heated to 130f. Once the blade has reached room temp, or you can hold it bare hands, temper it twice, once hour each, at around 400f.

Because the steel is very very soft from the factory, I do recommend that a normalizing is done on all of Aldo's carbon steels. For 1084, this means heating the blade to around 1600f and letting it cool in still air. Then we do this again at a lower temp, maybe 1500 degrees, air cool. Then again at 1400f, air cool. Then on to the hardening procedure outlined above. Normalizing is harder to do in a forge, because it is a little more difficult to judge 1600f by eye, compared to 1500f which is just a little hotter than non magnetic.

That is a very quick summation. Hope it helps you!
 
I'm expecting my first batch of 1084 from Aldo, this thread is just what I needed! thanks, Dan
 
Learn to watch for the Decalescance. This is a very neat phenomenon when your blade is hitting the critical temperature it will darken slightly as the carbon uses energy to move into solution. When the "shadows are done dancing" then the 1084 is ready for quench. The first dozen times I've done heat treat I had to depend on the pyrometer.

There are several videos and tutorials on decalescance. Watch them. Study them. This is some of the 'magic' that the previous generations of bladesmiths refer to.

BTW, decalescance happens at a higher temperature than recalescance. Always quench when the temperature is going up, not down.
 
I just heat treated some 1084, and originally had some troubles. I was actually getting the tip To hot and it wasn't hardening (file test). Apparently more isn't better. Good luck!

Farmer2
 
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