Excellent post, and excellent advice, Ed. I have done extensive testing and study of more than a few damascus combinations and 10XX series with 15n20 ranks near the top in several categories: appearance- it is beautiful stuff, performance- done correctly only a couple other combinations can out-cut it, compatibility- your comments are spot on, the curves match quite well, user friendly- this is the mix I use for demos because it welds so effortlessly Mr. Murphy has little chance in the demo.

One of the most discouraging comments I can hear from any maker or user is a blanket statement about damascus, e.g.- "damascus is pretty but doesn't cut as well as single steels" or even "damascus has special properties that will allow it to out-perform other steels". Both types of statements are equally absurd and reflect a sad lack of insight or consideration of the topic before speaking. I have seen veteran makers claim that only the fastest quenches should be used for "damascus", revealing an appalling lack of judgment in material selection, or understanding of the topic they are discussing. Damascus should respond fine to whatever quenchant the component steels would use, unless one is egregiously mismatching steels or using materials that will not harden.

Damascus is not "a" steel but the end result of a smiths skill in steel selection, forging, welding and heat treating abilities. It is any number of infinite combinations of steels and methods, making a single, standard outcome virtually impossible. There are superb damascus combinations and there are very ill conceived ones, and it all comes down to the skill and understanding of the maker. That is why it is probably most fitting that it is the material reserved for the obtaining of the Master smiths rating. Single steels leave much less to go wrong in the hands of Apprentice or Journeyman, introducing the endless variables of pattern welding raises the bar for the highest rating. The balancing act between "pretty" and "performance" is one factor that separates potential Masters from the rest, and those who achieve both are naturals for the stamp.

A guiding principle that has served me very well throughout my career is to never put anything into my damascus that wouldn't make a great blade all by itself. I urge all potential damascus makers to educate themselves about the principles of carbon diffusion to understand that much of what we have believed about hard and soft layers has been a very old myth. The definition of "damascus" is not high carbon and low carbon steel, as that will only result in all medium carbon layers in short order as the folding progresses. A good damascus is the result of two alloys of carefully chosen and differing chemistries, which will provide differing degrees of abrasion resistance and/or impact toughness and these are different from "hard" and "soft”.

Excellent info Ed and Kevin, thanks!

I wanted to throw one more note on steel selection into the ring here. While it usually isn't a serious issue, elastic modulus of the materials being used can sometimes become an issue. If the steels chosen deform at different rates while being forged, it can cause shearing at the weld boundaries if care is not taken. In my experience, this rarely pops up with simple carbon steels such as Ed has discussed above, but for the adventurous 'smith who is working higher-alloy steels or stainless steels it can become an issue. It can also be an issue with certain material combinations in mokume gane, but that's outside the scope of this thread, so I'll just leave it as a passing mention.

-d

|quoted:

Excellent info Ed and Kevin, thanks!

I wanted to throw one more note on steel selection into the ring here. While it usually isn't a serious issue, elastic modulus of the materials being used can sometimes become an issue. If the steels chosen deform at different rates while being forged, it can cause shearing at the weld boundaries if care is not taken. In my experience, this rarely pops up with simple carbon steels such as Ed has discussed above, but for the adventurous 'smith who is working higher-alloy steels or stainless steels it can become an issue. It can also be an issue with certain material combinations in mokume gane, but that's outside the scope of this thread, so I'll just leave it as a passing mention.

-d

this definitely an issue with certain steel combos. I remember trying L6, O1 and 1095 together and experiencing persistent difficulties with shearing. i eventually got something usable, but there was a whole lot of swearing and exasperation along with it.

This could be a very good discussion for helping others with information. The real factors are expansion due to rate of martensite conversion, ductility/malleability at temperature and coefficients of thermal expansion (how much does it move when heated slightly), modulus of elasticity would be pretty much the same for all alloys and would apply in the elastic range so would not conflict much.

The other three however are real problems in keeping the blades straight and the steel together. The worst is the rate of martensitic expansion (steel expands when it hardens, the greater the hardening the greater the expansion). Two things to look at here, how much alloying is present and how much carbon is present. With more alloying the more extreme or deeper will be the hardening, so steel with lots of chrome, tungsten, manganese etc... will harden much more radically than those without, and mixing them with steels that lack them will not only result in having to compromise on heat treat it will also result in very different rates of expansion on cooling. Of these Chrome is about the worst and manganese is pretty tame.

Different levels of carbon will also come into play because it will shift Ms (the point at which the steel actually begins to harden when quenched), a simple carbon steel with .5% carbon will begin to harden at around 600F when quenched while a similar steel with 1.0% carbon will not begin to set up until quenched to around 375F. In this case you will have one steel massively expanding and hardening while one is still soft and pliable and it will get pulled along with the other until it then makes the conversion and then a massive tug of war begins. This is one more reason why carbon diffusion is a good thing, because if you fold up enough layers the carbon will equalize.

Malleability at temperature is effected by heavy alloying like chrome, tungsten, vanadium, molybdenum etc… this will keep the steel much “stiffer” under the hammer as we have all felt with some steels. Mix such an alloy with a very simple steel and you will have one steel that is squishing and moving very readily between layers of rather stiff and unmoving material but having a weld union that does not want to move; eventually something will have to give.

If you combine some of the issues you can get a critical mass of bad qualities in the match up, for instance some of the worst damascus self destruction I have seen came about when 52100 was mixed in low layer count with a very simple steel. The combination of carbon deviation and chromium content can literally split a blade in half lengthwise. Many of us have seen that horror.

I really good test I have come up with for a potential steel mix, or to prove these concepts to doubters, is to weld your two steels up into a 40 layer, or less, twist. Forge it into a perfectly square rod and then normalize a couple of times. Good matches will corkscrew minimally, while bad ideas like say 1095 and L6 (real L6) will totally shock you on how much they will spiral around on you.

Even if things stay straight you still need to choose steels that will negate the need to sacrifice the heat treatment on one or the other in order to get what you want in a knife.

1080, 1084, 1095, W1, W2 mixed with 15n20...VERY GOOD STUFF!

Kevin,

I have a good quanity of 1030 and would like your thoughts about using a 1080/1030 mix with 15N20. Will this give me any difference in etch that is worthwhile if I keep the layers such as to not make them homogenous or am I simply asking for trouble?

Gary

If I were to put a billet up of the steels you're proposing, I'd probably make sure the 1030 had a piece of 15N20 on either side of it.

|quoted:

Kevin,

I have a good quanity of 1030 and would like your thoughts about using a 1080/1030 mix with 15N20. Will this give me any difference in etch that is worthwhile if I keep the layers such as to not make them homogenous or am I simply asking for trouble?

Gary

Gary, why the 1030 at all? Despite a common belief, all of my research, testing and experience has shown no benefit in adding lower carbon steels to damascus except when intentionally lowering the carbon content is desirable, which I have done with bloomery steel by adding simple irons. If you go with a 3:3:3 ratio your contribution of carbon from each would be .27%C, .24%C and .09%C for a total of .60% overall average billet content. So if you start with that and limit your 1030 to less than .25% of your billet you should still do fine.

Things like nickel and silicon content in an alloy will slow the carbon down but will not stop it. Pure nickel will stop it, but I will not even mention the results my tests have shown for pure nickel in damascus as it tends to upset those who like to use that material. Carbon "migration", actually called diffusion, has for too long been seen as a liability to overcome when it has in fact been an asset to the performance that many have gotten with mixing in low carbon materials. There are some issues that had more than one person scratching their head when carbon levels were kept exclusive within a pattern welded material.

As for the etch, you will only get a difference between the 15n20 and the other two steels which will basically be indistinguishable from each other. Carbon content offers very little in color contrast and this fades even more with diffusion. Alloying is the real key to contrast and Mn is your friend in the 10XX steels for producing a nice combination with 15n20.

Thanks, Kevin. That's what I was guessing but thanks for confirming. I have a couple of large rolls of steel banding that is the 1030 and was trying to rationalize a use for it.

Gary

I'm just a whipper snapper (at least at bladesmithing), and have been using 1080 and 15n20 per Mr Caffrey's excellent suggestion on this board and on his videos. It only makes sense to use like materials to end up with a successful product, at least when you're still learning. I just placed and order from Admiral for some 5160 to make some blades preparing for my JS test performance blade, again using the steel suggested by those who know.

I will have plenty of extra in the end since it comes in 264" lengths. Looking at it, it seems 5160 is very similar to 1060 with some alloying elements in it. Would this work well with the 1080 and 15n20 to add a little more visual appeal? Seems like it should weld up just fine, but just checking because I'm sure most of you have already used it in billets.

"As for the etch, you will only get a difference between the 15n20 and the other two steels which will basically be indistinguishable from each other. Carbon content offers very little in color contrast and this fades even more with diffusion. Alloying is the real key to contrast and Mn is your friend in the 10XX steels for producing a nice combination with 15n20."

This is precicely the reason I suggested that he sandwich the 1030 with 15N20, if he's going to be insistent on trying this steel in his mix.

|quoted:

This is precicely the reason I suggested that he sandwich the 1030 with 15N20, if he's going to be insistent on trying this steel in his mix.

I agree that it is a really good idea, I will often add some O2 into my mix and always seperate it from the O1 with the L6 otherwise I would get a black against very dark gray instead of a nice black/silver/dark gray.

I too was wondering how 5160 would weld up and look in a damascus blade? I've never done damascus before so I wasn't sure if 5160 would work, as I've also never heard anyone mention it for damascus. Plus, I have lots of the stuff and will be getting a bit of 1095, so if those two would work well together I would much appreciate the knowledge so I don't go out and waste material <img src=' http://www.americanbladesmiths.com/ipboard/public/style_emoticons//smile.gi f' class='bbc_emoticon' alt=':)' /> Thank you and interesting posts

Sorry this took so long to redo. Been swamped. Hopefully I got the picture right this time. <img src=' http://www.americanbladesmith.com/ipboard/public/style_emoticons//smile.gi f' class='bbc_emoticon' alt=':)' />

I've never seen this type of damascus before. What pattern is it and what metals do you need to us to achieve it? Thanks.

Forgot to ask if anyone knows that handle material as well.