Heat treating 1095 and 1084

[Ernie Swanson]

As most of you know i was planning on a ht oven build, Well right now it is out of my budget so I am going to do the 2 brick propane oven.

I have a few questions on treating 1095 and 1084, and the whole process!!

I have done alot of reading in the last few weeks about treating these two steels.

Can anyone give me a good process to doing these two steels?

so far I have gotten this

Normalise 3 times, bring to nonmagnetic(for 1095 hold for about 2 minutes)
quench, and temper 2 to 3 times at 400.

So To begin with the questions..............
Can anyone explain the normalizing process? I do not know how to do it!!

Is the McMaster-carr 11 second quench good for both 1095 and 1084?

Do I get the whole knife to nonmagnetic, Or just the blade?

Do I do anything to the knife to make the whole thing less hard than the blade?
I seen one tutorial on O1 that the guy did the whole process then put the edge in water and took a propane torch and heated up the handle and the spine above the edge.

I would like to try hamon lines, can this be done with just getting some satanite and using the 2 brick forge?

As far as testing the blades, I can do the brass rod test and do a bend to 90 degrees test, what do I want to see to have a good treated blade?
Is there anyone that does Rockwell testing?

I am sorry for all the questions but I am just trying to get this right.
I know I will have to experiment a little.

 

[A.W.Stovall]

I would probably hold off on the 90 deg bend. But thats just me

 

[Doug Lester]

Ok, heat treating is not rocket science, so relax a little. The purpose of normalization is to reduce to stress put into the steel during the forging process by allowing the grain structure of the steel to reform. To do that heat the entire blade, tang and everything, to non-magnetic, hold for several seconds to assure even, trough heating and allow to air cool. Repeating this process three times is pretty much the standard. Done correctly, it will also reduce the grain size as the crystals reform. Done incorrectly, too hot for too long, and you will actually grow the grain (crystal) size. Normalizing will also soften the steel for grinding.

For tempering, I generally just heat the blade section and not the whole tang as a hardened tang can cause production problems later. Even if you heat the entire blade, tang included, to non-magnetic, do not quench the tang. You must move the work from the forge to the quenchant as quickly as possible before the steel starts converting from austinite. That's why you will want the steel to get just a little hotter before quenching than you would generally have it for normalization. However, if you get it to hot you can have a problem with grain growth and warping.

Both of the steel that you listed can be used to form a hamon, but I recommend that you not worry about it to start with. The technique with the O-1 steel being heated with the edge in water is called drawing back the temper and is a method of differential tempering.

The brass rod test is good for determining if the edge is the way that you want it. The 90 degree bend test will destroy the blade. You will probably want to test an example blade to destruction occasionally, especially as you are learning, but it is obviously something that you will not want to do with every blade.

Doug Lester

 

[Wayne Coe]

Ernie, I assume that you are doing stock removal knives, not forging. If you are purchasing new steel it should come in the annealed state. That is as soft as it gets. So if this assumption is correct you do not need to worry about "Normalizing".

As Doug says, normalizing is raising the steel to the "Critical State" which for most steels is to non-magnetic and allow to air cool. To test for non-magnetic suspend a magnet from a small wire or chain. Slowly bring the heated steel close to the magnet to see if the magnet moves toward the heated steel. If it barely moves you can stick it back in the forge and turn the forge off. Leave the steel there until it is at room temp. If you are still needing to use the forge put the steel back in the forge for a couple of seconds and test again until the magnet doesn't move. Then place the steel aside (not on a cold piece of steel, preferably a warm fire brick or piece of ceramic blanket such as Inswool, Durablanket or Kaowool.) Allow the steel to air cool normally to room temp (not in a draft or anything that will hasten the cooling.

Annealing is the same as Normalizing,,,,,except, when annealing place the non-magnetic steel in an insulator such as wood ashes, lime, or vermiculite or wrap it in several layers of ceramic blanket. The intent is to cause the steel to cool as slowly as possible. The method mentioned above of leaving the blade to cool in the hot forge will probably cause the blade to be annealed rather than normalized.

In short, normalizing is softening the steel, reducing grain size, and reducing stresses.
Annealing is carrying these effects to the next step.

 

[LRB]

To harden you have to go beyond non-magnetic. I have no idea why this myth of quenching at non-magnetic is still promoted by those who should know better. You need about 75° more heat than non-magnetic before you quench. That would be around two shades of red beyond non-magnetic. Then try and hold it there a couple of minutes. You will be much better off using 1075/80/84, than 1095. 1095 is not easy to HT right, without the proper quench. 1095 requires a quench that will drop the heat from 1500° to below 900° in .8 of one second to get it right. Close, say 1 1/2 second cool down, will give a decent blade, but not to it's full potential. Slower than that, it will not hold a good edge. The other 10xx steels are much more forgiving and will out perform poorly HTed 1095.