OK, I want to offer this real situation that happened today and see what you guys think. I have an idea of what the problem was, but I thought it might be good to analyze the problem and see if we can figure it out based on what we know about how steel behaves.

Some of us makers set up at the Big Buck Classic in Little Rock where we forged and visited with the public, basically introducing the craft to the attendees. It's a beautiful, bright sunny day. It's now time to start forging a blade and It's my turn. One of the less experienced makers insisted that I use his bar of steel. I get the blade about half forged and all of a sudden I look down and there is a glaring crack in it. Honestly, I am shocked. I have never, ever, had a blade crack while forging. A few suggested that I forged it too cold, but I am careful about such things and did not believe that to be the case. So I cut it off and started another. This one seemed fine.

The next two guys forged, or should I say tried to forge a blade using the same bar of steel. When one got finished, he just handed it off to the next guy. Both were experienced or closely watched by experienced forgers and both were plagued by unexpected and shocking cracks in their blades. When I say unexpected, I mean that the cracks were in the edge, the spine, the ricasso of all places, and some running the length of the blade. You could actually see some cracks form as it was being hammered while red. Now, tell me that's not shocking.

Like I said, I think I know what the problem was and why. Not be a smarty britches, but I figured this is a good thing for us to figure out here. So lets let it sit a day or so and see if you guys come up with the same thing. I will answer some questions to be fair in case I have left out something that is a vital clue. Lin

Damascus or standard steel?

1084   3/16 X 1 inch

Good question.

Lin, Was it so sunny out side that you over heated the blade, not seeing the real color or temp.
Just a thought
dana

Hmmmm very interesting???????????? Ice cold anvil... windy...  are ya sure it was 1084?

Looking forward to the answer to this mystery...

Sounds like what happens when you forge over heated stainless or high nickel steel.  Miss shipped stainless in the place of 1084?

That or someone made up some crucible steel, formed a bar and called it 1084.

Another vote for overheated, maybe before he handed you the bar.  Huge grain growth from the overheating can lead to cracking while forging if  you don't re-normalize it to reduce the grain again.

• Members of the Arkansas Knifemakers Association will give knife forging, grinding, and cutting demonstrations. The State of Arkansas has more Master Knifesmiths than any other state in the Union!

Lowell, good suggestion, but I am certain from the circumstances that it is 1084 and not stainless. I myself recognize the bar size and, rounded corners, etc as being from Riverside Machine Shop. in DeQueen, Ar.

It was in the low twenties for temps. However, we heated the anvil with a torch to some degree before forging to break the chill.

I see I got you guys thinking. I will say that the bright sunshine is what we all were thinking leading us to believe we were forging too hot. But I have to say, that seems counter intuitive, to me at least, because, speaking for myself, I am sure I did not get too hot and most of the cracking I have seen in blades was from someone forging too cold. I was watching for that ahead of time. I did not use color so much. I could still see "even heating" remembering to protect the tip and I was waiting till scale formed on the blade to bring it out. Another thing, as I said I had a ricasso crack. That is the last thing that is likely to overheat on a blade. If I had over heated the ricasso, the thinner parts of the blade would have burnt up already.

Thus I am sure this problem was not from us forging too hot because of the sunshine or anything we may have done while forging.

This thing was eatin at me and I had to think about how could this individual bar of otherwise good steel, at least from appearance, be influenced to act this way while we forged it?

well i know close to nothing about forging but this is very interesting indeed.

Lin Rhea - I am not a knifemaker, but this post caught my eye since I worked around metals for a little while in my earlier career. Based on your description, believe the problem to be related to the quality of the steel.  If it was possible, would be nice to have a check of the chemical composition and a metallographic examination of the structure.  Some things that may cause the symptoms are "hot shortness", "embrittlement", or substandard "internal cleanliness".  Will be curious to see what it actually turns out to be.

George. Glad to have you with us.

This would be a reasonable suggestion from my description. But let me try to interjet this bit of information and see if perhaps you're not shootin too high to hit us. Karl pointed out that here in Arkansas we have the most Master Bladesmiths of any state. There was a grand total of one Mastersmith present at the event and he aint so smart sometimes. The maker that shoved the bar of 1084 steel in front of us is inexperienced as I mentioned and I "think" there was something he did not tell us about that bar, something he just did not know to tell us. Something that lead to this puzzler.

I wont string this out much longer. There are just some things about people that you cant foresee or predict and I think it is a people problem that got us here. You guys dont know this person so you are at the disadvantage.

A clue to what I think is the steel's problem:

Quenching oil

is it possible that the bar stock was not annealed before forging? i know nothing about forging but just a guess that maybe by the steel being hardened it had to much stress and cracked?

Was it round rod then turned into bar stock?
In other words was it messed with before you forged?

One more guess, I think he tried to annel the steel and was confused about the process and quenced it in cold oil, which hardened it and made the steel crack under stress
Dana

KSM, The flat bar that comes to us for forging blades has been rolled steel either annealed or normalized. So it's not supposed to have been hardened, but that is where I say the people problem comes in. As Kevin says, somebody messed with it before we got it.

Here's what I think. I think the maker that gave us the bar, who is a nice guy and is always there to help out, did something to it without thinking to fully harden it before we got it.

How do you heat your quenching oil? I sometimes heat up a bar of steel and stir it around in the oil till I get it warm enough(real careful with Parks 50 though). I use a chunk of D2 welded to a handle since I dont plan on using the D2 for anything else.

I think he grabbed a piece of his 1084 sometime previous to the event, heated it up and stirred his oil with it thinking he was just heating the oil, never realizing that he was fully hardening the bar at the same time. So basically he quenched it and right then or over time it developed spider web cracks all in it. This would explain them showing up at odd times (even while red hot) and places on the blade and the cracks running in weird directions. Once the tiny cracks were there, we were fighting a losing battle forging a blade. Once we changed to a different bar, mine, we could forge just fine.

I "figured" this out while driving away from the event, not by asking the gentleman who gave us the bar of 1084. So, until I can see him again to ask him a few questions, I am not completely sure, but I think this is what happened.

edited to add: Dana, I was writing while you were.

You all had good answers that made sense. The problem was a factor that we had no control of.

wellawlb... now it makes perfect sense     Sure had me scratching my head but almost knew it had to be a steel problem... Thanks Lin

Doug

That was very interesting.  Now...what about the blade you made after the one that cracked?
Is it at risk of cracking down the road?  Is it to be considered a good blade?  Or are there microscopic cracks waiting for their time to appear?
Dan

Dan, I conveniently forgot to bring it home. At the time, I was not sure what the problem was, but I knew I did not want to get it mixed up with my hunters I have forged and ready to grind.

Before you "forgot" it, did you stamp it "ANDERSON"?   :D