Damascus HT Question

D

deker

Joined
Nov 14, 2005
Messages
3,496
Hey folks,

This evening I had a maker who is teaching me hand me a mostly finished knife he was working on and tell me to finish it. He mentioned that it would need to be heat treated again though since it apparently didn't come out right when he did it. It's ~300 layers of W-2 and 203E. What would be the proper temps and quench medium for this combo?

Thanks for any help,

-d
 
Generally you heat treat for the higher carbon component in a damascus piece. If there's too much 203, mild steel or other unhardenable substance, you won't ever get good hardness because your carbon average is pretty much shot.
Combinations like 1075/1086 and 15N20 are nice precicely because you can get contrast from two materials that will harden pretty much the same.
If you must salvage a knife with below-par carbon average, I have done it by having it professionally deep carburized to the end that the carbon average is raised something like .50 (don't remember exactly) throughout. This was a process to send the carbon about 3/16 deep all around, which should be full saturation for just about any blade-like object.
It worked, at least in that the piece hardened nicely and didn't destroy the contrast, which surprised me since the hardening problem was due to the use of too much 1018 with 1095. I destruction tested one of the two pieces I had treated, then hardened and it performed perfectly. This is usually not a cost effective solution, however. I just avoid using low or no-carbon materials any more.
Of course, all this might not be relevant to your knife. Just treat like W2 and see what you've got. I would Marquench a ground knife in this situation, but without a salt pot, I think it would be something like 1500 into light oil and temper at 350 or so, depending upon the size of the knife.
 
That's the falacy of using a low carbon steel in damascus. If you want a good working blade use a mix of two steels that have similar and suitable carbon levels .If you must use a "white " alloy for damascus like 203 or pure nickel make sure it's in a small percentage of the mix .
 
I was so happy to see that you have a good grasp of what is actually involved after I saw the title of this thread. You competely redeemed yourself by approriately asking how one would heat treat that particular mix of alloys. :)

One of my pet peeves, is when folks say that you must heat treat "damascus" like this..., or that there are oils made specifically for "damascus", I understand that many of these misconceptions are based upon ignorance of the materials, but 9 times out of ten if a person must approach the heat treating of a pattern welded material differently than a decent hihg carbon steel, the stuff isn't worth the trouble because they have fallen into the pitfall of dumping too much unhardenable material ino the mix.

As mete has pointed out 203 will work if you keep the ratio low enough to just give you that striking contrast that it can provide and mix it with a good hypereutectoid (well above .80% Carbon) so that it can spare some carbon to prop up the 203. W2 certainly has the ability to do this and this mix, when done in proper proportions, has made some very nice knives. If you really want to nail it, you will need to get the ratio of 203 to W-2 you have in that blade and then adjust for it. Either way, W-2 will need to be quenched as quickly as you can without warping or cracking it, so use a very light oil. Heat to 1475F with an 8 to 10 minute soak and quench immediately.

We would all be better off if we thought of pattern welding as a process and not a material, for trying to describe or label all of the possible combinations is like asking "how long is a piece of string?". An then the makers of the material may put more thought into what they mix and why. When I deviate from my normal mix I often spend some time with a pencil, a calculator and eventually a set of scales to determine the ratios that I will want for the given outcome desired. Then I can heat treat it once, although this is bad news for the guys who benefit from an oops like the one you have.;)
 
Thanks for the help folks. Unfortunately I don't know what the ratios that went into this piece were. I'll see if I can find out from the gentleman who made it. I have a feeling that it was close to 50/50 though, so it may just not harden well as-is. Who would I call for a deep carburization service, and what is it likely to cost? This is a piece given to me by my mentor to finish and I'd like to really do an outstanding job on it so I can present it back to him as thanks for the time he's spending with me (his intent was to give it to me, but the way I see it, now that it's mine I can give it as a gift if I so please ;) ).

I know it was made in a damascus class taught by Rob Hudson some time ago, so if anybody else has taken a class from Rob where they welded up W-2/203E and has a clue what proportions might have been, I'd appreciate any insight.

Also, since we're on the topic, how does one figure out what neighborhood the final carbon content would be in for a given set of alloys in a given combination? I figure there must be a formula based on points of carbon in each alloy and proportions of alloys used, and I bet it's a simple as I figure, but I'm asking anyways :)

Thanks,

-d
 
Final carbon content ? The carbon will not be uniform . How much diffusion of carbon depends on how long it's above critical temperature and how many times it's folded. But if you have a 50/50 mix of 1020 and 1080 obviously a thorough mix will give you 1050 !
 
mete said:
Final carbon content ? The carbon will not be uniform . How much diffusion of carbon depends on how long it's above critical temperature and how many times it's folded. But if you have a 50/50 mix of 1020 and 1080 obviously a thorough mix will give you 1050 !
Click to expand...

That's about what I thought. I just wasn't sure of how carbon migration actually worked. I guess this explains the reason for san-mai style blades then :D

Thanks,

-d
 
I used a local 'Hiderlighter' industrial heat treating location. The bigger pro shops usually have better capabilities, but keep in mind you're venturing into lightly trodden ground (which is often more frustrating, but potentially rewarding). You'll have to explain what you have, they'll look at you funny and want to charge you a full-batch price. I got lucky and peaked someone's curiosity, so it was cheaper, but still about $100.
Frankly, I would set the piece aside and spend my time on material I know is 'right', but if the piece is very important to you and nothing but junk otherwise, what the heck, try it. If the knife is already finish ground, you may have trouble, because really thin sections will want to warp. But like I said, I tried this as sort of a despiration play and was pleased with the results. (Better to aviod the problem in the first place, though).
When it comes to alloys in a pattern welded mix, I avoid unhardenable material all together on larger performance pieces like swords. I've found even a small amount of pure nickel in a sword is noticably detrimental to its characteristics. Knives-- not so much as long as it's not on the edge.
I think the best advice is when making a blade, to use 'color steels' that will harden period.
 
If you can't get your blade to harden, I would contact Nick at
http://www.heinzelmanht.com/knives.htm
I'm not sure they do the kind of thing we're talking about, but Nick's a knife guy, friendly and (like many of us) open to experimentation with steel. probably a good place to start.
Extra note: These guys do very nice color case hardining which is reason enough to bookmark 'em as far as I'm concerned.
 
If what you want is suggested numbers, try these:
Bring to 1400 and hold for 10 minutes, Ramp to 1550 and hold for 10 minutes,Quench in fast oil (parks AAA).Temper at 400 twice.
Stacy
 
Thanks for all the info everybody. I still need to take some time to evaulate the condition of the blade as it is now, but if another HT is required I feel a little better equipped to handle it than I did yesterday. Since the blade is fully ground, I'll try to do any further heat treating in a real oven with tool wrap, etc to avoid losing any more metal to scaling. Hopefully, if I have to re-do the HT I won't have any warpage...

Thanks again.

-d
 
I used to use quite a bit of 203E a number of years ago, it makes very good looking steel and with the right mix a good performer. I would mix 5 pieces of 1/2'' 1095 or W2 with 3 pieces of 1/4'' 203E and come out with a carbon content in the billet of .70 - .75. Darrel Meyer uses 1095 / 203E and has for years, good stuff if done right.
 
I meant to type Park's (Heatbath) #50 for a fast oil,not AAA which is a medium speed quenchant. Sorry.
Stacy
 
to get an idea of final carbon content you would divide the carbon contents of that individual alloys by the percentage of the billet they will be, add those number together for the final carbon.

Example: 5 layer starting billet, 3 layers O1, 2 layers L6. The billet is 60% O1 and 40% L6. Lets say the O1 has .9% carbon and the L6 has .75% carbon, mutliply .9 by the .60, and .75 by the .40, and you will see that the O1 is contributing .54% Carbon and the L6 .3% carbon.

Add the two together and you will see that you blades will have .84% Carbon.

It is very simple mathematics (it has to be if I can do it:( ), yet if you do it on many of the popular mixtures you will find that often the final carbon is below .5%, demonstrating how seldom many damascus makers put any thought into what is going into their mix versus the final product. This is what has given rise to the unfair statements that "damascus" won't hold an edge as well.:(

Many folks make good mixes that include 203E because they know the math and keep the percentages adjusted properly to allow the higher carbon steels to lend some mojo to the 203E.
 
Right now I'm kind of curious why anyone would choose 203 over say, 15N20. They're going ot look about the same, and one won't tax your carbon average. ??????
 
JCaswell said:
Right now I'm kind of curious why anyone would choose 203 over say, 15N20. They're going ot look about the same, and one won't tax your carbon average. ??????
Click to expand...

Ditto here. Like I said, I know this was done in a class @ Rob Hudson's place, and I can't imagine why he'd pick 203E over 15n20. The contrast in the steel is great, but 15n20 should be ablout the same right?

Also, just to check, the 203E in this would show up as the silver bits in this after etch and the w-2 would be the darker etch right?

I'll try and post a pic in a bit of I can get a good closeup.

-d
 
JCaswell said:
Right now I'm kind of curious why anyone would choose 203 over say, 15N20. They're going ot look about the same, and one won't tax your carbon average. ??????
Click to expand...
203E was popular before 15N20 was being used. It also etches better or brighter, were 15N20 comes out of the etch a bit dark or dirty looking and usually needs to be rubbed out after or buffed. 203E as more nickel, it also comes in 1/4'' or thicher. I'm not saying it's better than 15N20 just different and as I said before, performs very well in the right mix. I have a lot of 1/2'' to 2'' thick tool steel that works well with 1/4'' 203E, I also use 203E and pure nickel in damascus for guards and bolsters. Some of the nastiest looking steel I've made was out of 1095 and 15N20 with a low nickel content and the other was made with Admiral's L6, agian with low nickel. It's all good, you just have to know what to do with it.
 
Now that you mention it, 203 would seem to be particularly well suited in a mix for fittings and stuff that will be handled.

sunfishman said:
15N20 comes out of the etch a bit dark or dirty looking and usually needs to be rubbed out after or buffed.
Click to expand...

I haven't run into this, though I suppose everything looks dingy next to pure nickel, and since I haven't been using that or 203 for years, it may just be what you get used to. (I use a pretty strong, fresh Ferric Chloride solution. Maybe the shorter etch times prevent excessive darkening??)
--I have noticed an interesting effect in Miratic acid which I use to descale forgings. The Miratic acid causes the 15N20 to go black and the carbon steel to come up white --- sort of the opposite effect of the Ferric Chloride. Of course a few minutes in Ferric Chloride switchs it back.

Don, I viewed your site the other day. Very Nice Work!
 
"Don, I viewed your site the other day. Very Nice Work!"

Thanks J,

I use a lot of 15N20 and like it, the nickel content can very from less than 1% to over 2%, the stuff I didn't like was around 1%. I now get my 15N20 from Kelly Couples at around 2% nickel, he has it tested and knows what's in it. 203E etches a silvery white that I quite like, if I remember right it has around 3% nickel. You're right about the fresh feric and a shorter etch for better results, I need to remember to change mine out more often.
 
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