Ed,

Bob suggested I post the question over here to you. If you have time to read this link on CKD folder forum. I would really like to know whether I caused the damascus to crack or if was more likely a bad weld. Also if it is preventable and how.

Link:

pub42.ezboard.com/fcustomknifedirectoryforumfrm17.showMessage?topicI D=75.topic (http://pub42.ezboard.com/fcustomknifedirectoryforumfrm17.showMessage?topicI D=75.topic)

Thanks for your time

Hi Tony!
I have heard several others say they have had problems with the Thunderforge stuff. The first thing I need to know is what are the steels used to produce the damascus? This very likely will help me pinpoint the problem.
I know this stuff is cheapo import, and my first instinct is to tell you to buy good domestic damascus, and pay the extra money. Steel is one thing that you certainly get what you pay for.
I also saw your question of what normalizing is............ When steel is hammered it develops internal stresses, that can literally cause the steel to crack, making it useless for blades. Normalizing is usually done after the blade has been forged. In the process the blade is brought to critical temp, and allowed to cool in still air. I make the analogy of a person riding in a car for a long trip, then getting out and streaching, which works out all of the kinks and tightness brought on by the long time in a cramped car. More or less a relaxing, which is exactly the same effect that normalizing has on steel. I usually normalize at least twice during the knife making process, once right after I finish forging, right before the first annealing, and then again after grinding, right before the first hardening cycle.
Post up what the information sheet on the Thunderforged damascus says the alloys in the steel are, once I have that info, I'll be able to tell you more.

Ed-

I haven't read his story yet on it, but I know that I have some and the sheet says that it's 1095, O1, and 8% nickel.

I ground a 10" dagger and gave it to Bruce Bump to heat-treat...it cracked right in half.

Bruce had done some of it for me in the past, and did everything the same (followed their instructions)...so I just figure just what you said---You get what you pay for.

I did get some excellent buffalo horn from those guys though, and they were excellent to deal with, so I'm not bashing here.

But the steel did disapoint (although the pattern/contrast is great).

Nick

Ed,

It is just like Nick said. O1 and 1095 and nickel. THe instructions I got don't say anything about normalizing. And for heat treating it gives two options one for oil and one for brine water. Start at 1400 to 1500 degrees. I used 1450 in my oven. I tried both brine water and olive oil, for the oil, and still got the crack. Both cracks on both blades appear to be right along the pattern line. Although the second one is hard to really tell. Both were cracks were about 1/4 inch long. Some have suggested a bad weld?

Another weird thing is they give two tempering ranges for the two different steels O1 &1095 instead of one tempering range for the damascus.

I'm not trying to slam Thunderforge either because I don't know if it's me or their steel or a combination of both. You are not the first that told me I get what I pay for. I just thought, I would try an experiment before I gound on some good more expensive stuff. But in retrospect all I got was more experience grinding. It does have a great pattern and it is nice and tight for making folders. And it does make some really nice bolsters so I will probably buy some more just for that and splines. But for blades ...... I don't know.

Another weird thing is they give two tempering ranges for the two different steels

There's the answer!! O-1, 1095, and the culprit in this case.......NICKEL! 1095 and nickel will work fine, O-1 and nickel can work, if a person is careful while forging it. From the pictures I've seen of the thunderforged damascus, my guess is that it's more a mass produced type steel. This leads me to believe that quantity is the main goal, versus quality.
OK, here is my theory................
The cracks you got during hardening probably run right between a layer of nickel (bright line in the steel), and a darker line (likely the O-1). Because of the different expansion and contraction rates of these two materials, combined with what is likely a bad weld, the materials simply can't hold together when quenched. The O-1 is contracting at a much higher rate than the nickel, and if there is a weak spot, the steel will literally pull itself apart!
The part where you mention about the instructions listing two different tempering temps is enough to make me suspicious! Sounds to me like somebody has just taken the info supplied from the producer of the base materials, and without any experimenting or research, thrown the product on the market, hoping to make some $$$ off the popularity of pattern welded steel.
Things like that tick me off! There will be someone, somewhere, who's only experience with damascus will be something like this, that fails either during the production of a blade, or during usage, and that person will have a tainted view of all damascus from that point on.
I'd be calling whomever sold you the material, and asking questions like "Why are there two different tempering temps listed in the instructions?" That was a dead give away to me. I might be able to swallow two different tempering listings, provided each equated to a given Rc, but not if the temps listed are for the separate alloys in the steel.
Most reputable outfits will warranty their steel and replace bad pieces. I personally think that both you and Nick got "bad pieces", and I suggest contacting the folks you purchased from. If they won't replace it, or if they give you the run around, forget the stuff, and buy domestic!

Tony,

That is why I recommended you come to Ed's forum. He has a sneaky way of figuring out what is going on. The subtle things the rest miss, ED gets.