Which metals can be forge welded together

[Luckie24]

I have recently started making Damascus billets and in some of my research ive heard "you have to have compatible metals". I don't really understand what makes two different steels compatible for forge welding.  Mainly I'd like to know what I can use out of my scrap pile (since im a farmer with 4 generations worth of scrap). I have tried an old duck foot shovel, ( basically a hoe for plowing ground ) with a stainless saw blade. These haven't really been working and I'm not sure if it's my ability to forge weld or if it's the materials. Thanks. 

[Frosty]

Welcome aboard Luckie, glad to have you. If you put your general location in the header you might be surprised how many members live within visiting distance. Working with an experienced smith will let you learn things in an afternoon that could take weeks or months figuring out on your own. 

Stainless steel has a high chrome content making it VERY hard to forge weld without using dangerously aggressive welding flux. By dangerous I mean you need to take special precautions against  toxic vapors dangerous in small concentrations with long term health effects. 

There are guys on Iforge who pattern forge weld stainless blades but they have years of experience. You can buy their books for directions and recipes though.

Getting started stick to steels without much if any chrome, spring steel has chrome in it but not enough to need special flux. You just picked an incompatible metal for your skill levels. Join the club I don't think anybody who's been doing this for any length of time hasn't tried things above our abilities. It's what makes things fun and what the hey, it MIGHT work.

Frosty The Lucky. 

[Luckie24]

Thanks frosty. I hadn't even thought about stainless being the issue. My next question would be how to decide which scrap metals would contrast each other enough to be visibly "Damascus"

[Steve Sells]

Using any scrap is a crap shoot try band saw blade and pallet straps. experiment

[ThomasPowers]

Nickel makes for a bright line in the etch and Manganese makes for a darker line.  If you don't know the alloy content of what you have it's like handing you a glass of water and having you guess if it was potable or not...

Experiment!  You don't need to weld a billet up to test etch material to see how it etches!

[MilwaukeeJon]

The other thing to consider, beyond trying to figure out what alloys you might be working with, centers around what you are making. If you forge weld a lower carbon steel with a higher carbon nickel steel you might get a nice contrasting etch but it also would not make a very useful cutting edge on a knife or chisel.

Because I don't have a power hammer and making a billet is a chore, I'm a bit of a chicken about all this and only forge weld with known alloys, typically ones I've bought from one of the major steel distributors used by knife makers.

[Latticino]

Another issue with compatibility that you should consider if you plan on making tools you intend to harden and temper is the relative heat treatment procedures for each metal.  As should be obvious it is best to use materials that have relatively similar heat treatment regimes, if possible.  If you combine a metal that has a fast quench requirement (like 1095) with one that is much slower  and quench with a fast quenchant to get the most out of the 1095, you run the risk of cracking the other.  My understanding is that 1084 and 15N20 have very similar compositions, with the exception of the trace alloying components that make one etch as dark and one as bright.  That is why they are often used for pattern welded blades these days.

[Steve Sells]

the other issue is expansion/contraction and hardening times and temps, if one hardens before the other they can pull apart, since there is a dimensional change upon hardening

[MilwaukeeJon]

So back to Steve's earlier point, experiment on the big pile of scrap but do so knowing that the unknown materials will likely lead to a higher rate of failure (of all sorts) and also may result in performance shortcomings depending on what you are making.

[anvil]

If it is a farm scrap pile and it's pretty old, I bet you have an old wagon tire and probably an old buggy spring.

They forge weld together very well and make a great contrast.

The tire will most likely be wrought iron and the buggy spring a high carbon steel.

I made my first knife out of this and did 700 some layers. It made a beautiful pattern and a serviceable knife. It's a great way to start.

[ThomasPowers]

Also think about San Mai where it doesn't matter if the outer layers harden or not and you can choose a core steel that hardens quite well. I've used an old Nicholson file for the core once when I was experimenting with a billet; but didn't think it was the C level I like in a knife.  It's my primary camping knife now and the one I used to cut a sliver off the back of my Ti eating knife when I was arguing with a Titanophile about it's use as a blade.

[Purple Bullet]

On 5/5/2020 at 1:57 PM, MilwaukeeJon said:

The other thing to consider, beyond trying to figure out what alloys you might be working with, centers around what you are making. If you forge weld a lower carbon steel with a higher carbon nickel steel you might get a nice contrasting etch but it also would not make a very useful cutting edge on a knife or chisel.

So is the purpose of pattern welding, or Damascus just for the "look"? I've made a couple of cable-damascus knives and they turned out OK. Hold an edge pretty well, but I'm thinking about trying some multi-steel billets now that I have a power hammer working. I always thought (just an assumption, I don't have any documentation) that the whole point of Damascus was to combine the hardness with toughness and that it was desirable for both metals to intersect the edge. Twist, feather or ladder would lend itself to that, raindrop would not. The reason, and again, I'm supposing, is that the great "secret" of Damascus knives  was they never (or rarely) needed sharpening due to the fact that as the edges wore, the softer metal wore first and left  sharp points of the harder metal, making in effect serrations.  Is this right?

 

[ThomasPowers]

No, unless you have a carbon blocker between the HC and LC layers they will even out in carbon content after about 4 times to welding temp if your layers are fairly fine.  This was all worked out a couple of decades ago by Daryl Meier as part of the Damascus Research Group at the Southern Illinois University at Carbondale.  Their work put paid to a lot of urban legends about pattern welded steel using micro hardness testing and other metallographic instruments---which doesn't stop them from still being spread!

Tougher usually is from having a lower carbon content from the mixing of steels.  Of course you can make both (or more) steels high carbon to end up with a HC result, minus the decarb from the welding, of course.  I have some 1.2%C old Black Diamond files I use to juice up billets to help counteract losses and melding.

[Buzzkill]

No, that is not correct.  The main point of pattern welding is the pattern itself.  Some techniques, such as san mai do use a softer/tougher metal as a sleeve for the harder, more brittle higher carbon insert to get a "best of both worlds" result, but the cutting edge is not a mix of the two steels (or it shouldn't be anyway). 

"Original" Damascus steel, sometimes referred to as Wootz steel, was superior to most steels available when it gained fame.  It had a recognizable pattern due to the technique used to create it - crucible steel.  It would still be considered a mono-steel though.  The high carbon mono steels available today are generally superior to anything produced centuries ago.  You may also see a reference to blades made from steel folded X number of times with a claim that it keeps the blade sharp as it wears. The purpose of that was to ensure a homogeneous piece of steel rather than the folding creating a bunch of thin layers that would wear in use and keep a sharp edge.

[ThomasPowers]

Wootz may be a "monosteel" but it's certainly not very homogenous!  Also remember that all crucible steel produced and used for weapons was not Wootz; Dr Feuerback discusses this in her thesis on "Crucible Steel in Central Asia".

[George N. M.]

One of the original purposes of pattern welding in the Early Middle Ages was to stretch the supply of good, high carbon steel and to add some flexibility in swords.  Later in the Middle Ages when larger pieces of consistent steel were available the use of pattern welding, particularly for blades died out.  You may see pattern welding in swords of say, the 8th or 9th century but not in 13th or 14th century blades.

"By hammer and hand all arts do stand."

[Purple Bullet]

Thanks for the clarifications. On the one hand, that makes me not so hot to trot on getting into pattern welding, on the other hand I always liked the rain drop pattern if I do try it I'll do it without the false impression I'm making something for function rather than for show. Otherwise I may just stick to cable. It's fun, makes a good knife and with the coming demise of the oil industry around here there will be lots of material to work with.

[ThomasPowers]

It is functional; just perhaps not as good as a monosteel---and much more dependent on the skill of the maker!   Remember every car doesn't need to be a Maserati!

And while not pattern welded, there was still substantial welding of materials even into the 19th century---look at how shear steel was made.  I bought a copy of Manfred Sachse's "Damaszener Stahl" in the German edition; just for the picture of an etched blade of a rapier from 1600 CE showing the welding of differing materials together.