Trying to understand

J

Justin Howell

Joined
Feb 11, 2012
Messages
28
Hello again fellas, I have been killing some time this afternon before having to go back to work and have tried for Lord only knows how long to come up with a tutorial about Heat treating 1084 steel. I have read many things and have yet to be able to make heads or tails of it.

Some guys are saying, get it non magnetized and quench, some are saying soak 10 muinutes at 1500 degrees. Some are suggesting that you heart treat it 2 or three times etc... I am getting really confused. So if you guys do not mind, please just tell me what the norm is for this steel, cause everything i have read says the heat treatment is the difference betwenn good and great. And I would like to know a general understanding of why before I get started. iIplan on sending my first knife or so off, but I intend on heat treating my own after that so, I would like to know before I get started. Still waiting on supplies. Here is my breif understanding of the process.


1. Cut out knife and shape by grinding, file than sanding to smooth. I assume to a silky finish as to minimize sanding after hardening has occured.

2. Heat treat to 1500 degrees or non magnetized for how long?. Then quech in Veggie oil. Explain why 1500 degrees seems to be what everybody is saying to start with please. Is this where it becomes non magnetized.

3. After the knife has returned to room temperature, oven bake 400 degress for one hour 2 times, allowing the knife to return to room temp in between. Does this have to be dome ASAP after the heat treating or can it be accomplished by getting 8 or 10 blades heat treated and then tempering them all at once?

4. Then re-sand, to silky smooth, wrap up blade to protect. Unwrap handle. Finish handle. Then unwrap blade to completed knife and hope their are no scartches on the blade to be reworked.

I assume the final edge in this process meaning, the edge right before one would call it sharp should be put on the knife before hardening. And what I mean by that after knife is completed, just honing work on stones would be all that is needed. I know this sounds dumb, but I am in the unknown and trying to get a game plan on this thing. A better understanding of what and why will help. Please correct and/or give me your .02 cents worth. i need it. God Bless
 
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Sounds about right. 1084 does not need a soak from what I understand, but can be soaked. However, I do not worry about it.
 
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Well, am I right about the other things? There has been 11 people to look at this, be nice if someone would chime in and help me out here.
 
Everything looks good to me. Feel free to correct me, though.
Whoops, Just realized what I was commenting on. I will edit my posts.
 
If you have an IR thermometer, digital thermometer with probe and can monitor the exact temperature of the steel you'll get better results with a soak of at least 4 to 5 minutes at 1475 to 1500 degrees farenheit, longer is also OK if you don't exceed that temperature. If you can't monitor the exact temperature it's best not to soak, just bring it up to slightly above non-magnetic (1414 degrees f) and quench.
 
Justin, look up a book called Fundementals of Metallurgy. It will help you understand exactly what's going on inside the steel. Cool book, but you need to read it a couple times to understand it. As far as HT info, I'm going to watch to see what everyone else says because I don't know either.

I would also direct you to the "Working the three steels" sticky at the top of this forum. Actually all of them. They are great too.
 
It really depends on what equipment you have. If you have a kiln a short soak would help... if not, don't worry about it. You've already done the hardest part by coming to the wise descision of starting off with 1084. It is the perfect steel to learn on.

1084 goes into solution sooner than any other steel. So you can get great results with the simplest of methods.

DO NOT BRING THE EDGE DOWN TOO THIN BEFORE HEAT TREAT. If you have a kiln take it to .030" or so and if you are heating in a forge, leave it +.060 until you get used to it.

1500F is far enough past critical temperature to get everything into solution nicely. Non-magnetic(aka, curie point) happens at 1414F, so you need to go as little past that for good results. 1084 is stable enough not to worry about immediate tempering. You can water quench inbetween cycles... there is no chance of hurting the blade and a good chance of improving it's resistence to cold embrittlement.

At it's simplest
-Heat until non magnetic then count a few seconds more.
-Quench in oil
-Temper at 400F, then check your edge hardness and raise temperature as needed. At least two cycles at 2hrs each.

There is lots of info in the stickies... I suggest you take some time to look through them...... welcome to the addiction!
 
Your on the right track, like Rick said leave yourself a liitle fat for post heat treat grind to final edge.
Take that 1084 to non mag and quench in that cooking oil you got put a temper on it, handle it, sharpen it, TEST THAT EDGE then give it away, and build another.:thumbup: GHaile
 
What is normalizing and do I have to do it to make a knife? Or do I just shape, heat treat, temper?

You gotta remember fellas I do not know what all of this is. Hence my first question. I have read all the info I can find including the above links before I asked these questions, and the three steal threads and I quess I am trying to consume to much material at once because it is unknown to me. So I am having a hard time understanding because this step is not listed in all the tutorials I have read and I do not know if it is a no brainer not be mentioned in all tutorials, or is it different techniques, or if it is something other than making a knife that I don't have to do.

God Bless
 
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Justin... I trust you will take this the right way as I only want to help but I wouldn't make a knife until you understand these basic steps.

Forging(unless you are strictly stock removal)
Normalizing
Annealing
Austenizing
Quenching
Tempering

All of this information is in most of the links you have looked at... you are just not recognizing it... which is why you need to do some reading. There is no express route to becoming an honest knifemaker.

If you just need to make a knife and heat treat isn't necessarily something that you want to take on, there are several heat treating services that will handle that for you.
 
Normalize

Normalize — Normalizing is the process of heating a ferrous alloy to at least 100-degreesF above the transformation range and then cooling the material in still air to a temperature lower than the transformation range. The process produces a recrystallization and refinement of the grain in the material that results in uniform hardness and structure. Many high strength components are normalized prior to the harden and temper process for the purpose of optimization of the mechanical properties.
from: http://www.diamondht.com/capabilities/normalize/

Normalizing is just heating the steel close to critical temp, and letting it cool to black before heating it for the quench. This relieves internal stresses in the steel, especially if forging, and reduces the chances of warping during the quench. I don't use 1084 steel, just O-1 and I usually normalize twice.

randy

ETA: Rick types quicker than I do and he's right. I sent the first 5 or 6 knives I made to Texas Knifemakers Supply for heat Treat. Peter;s Heat Treat has a very good reputation here but I have not personally used them.
 
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Rick, I am going to use an out side service for heat treating the first several blades. Just trying to put meaning to the thousands of sentences consumed. I understand what those terms are but just needed to know if it was something I should do always. After settling down and thinking about it I assume annealing and Normalizing is to prevent cracking durning ht by stabalizing or relaxing the steel. And so on and so on. I just am confusing myself by reading so many tutorials by guys talking to guys who know what's going on, and having no hands on expierence to relate to. So while I am going out of house to heat treat these first blades, I was on the fast track to understand why and what for. Gotta make me a better knifesmith if I understand that but I assume that the answers to this will come in time because researching this site has led me to the other thousand guys that asked these exact questions never got the "quick and easy" either because their must not be a quick and easy way to answer this.

I am like a kid on Christmas day waiting for the time to open presents waiting on my steel to get here to begin. God Bless
 
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You have a good attitude, Justin. Many folks start off sending blades out for heat treat... and just as many folks who know the principles of heat treat still choose to farm that part out for different reasons(Time, money, location, etc...). It's all good.

All those meaningless sentences will begin to make sense, then you'll really be hooked. The more I learn, the more I realize how little I know.
 
Here is a simple chart for various steel types. It's neither complete, nor absolute in it's accuracy. However, it's a good starting point that I find very useful, and others have found useful. Most useful, you find trends among various types of steels and you can develop your own recipes as needed.

View attachment steel chart.pdf
 
Note:

Quench in WARM oil: ~130 degrees F.
pre-heating the oil reduces its viscocity to the point where it can move heat away from the blade properly due to improved convection currents in the oil. (don't know if 'convection current' is a technical term, but I think it conveys the meaning)

Step 5 (you didn't number it): I do NOT put a final edge on the knife pre-hardening. Anything close to sharp is dangerous while you're doing all the finish work. I heat treat with the edge at 0.020" or less (ideally less!). Then put the thing on a coarse stone until you've created the proper edge bevel, then hone on a finer stone or two. YMMV, I'm sure more experienced makers than I do it a variety of ways.

-Daizee
 
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