Mittwoch, 21. Juni 2017

The knife that happened... ;-)

 This is yet another tall Fimbulmyrk tale... but i daresay you´re accustomed to weird stuff like this by now. There are a lot of extremely weird coincidences in my life indeed... it all started with a hike from the bus stop  to the ironforge. I had a schedule what I had to make or what I at least planned to make. On the way I first encountered something. At first I thought it were a stray dog, but as I came closer I saw it was a fox, only that it was a blonde one. It was by absolute coincidence that I followed him for quite some time, until he made his merry way into the thicket.

I want to make sure you understand that I am not saying that this event had anything to do with what happened next. It is linked to the other event by mere coincidence of course. Or not at all. Near Gut Ahlhausen, the manor in the neighbourhood of the ironforge, I found a right treasure hoard of bloomery steel, among which there also was an ingot of already refined steel. It turned out to have an estimated carbon content of about 0,5-0,7%, and I could not resist probing it by forging a blade from it.

Now this is a very special event to me, and a very special steel. It was a bit like a belated birthday present. All you faithful readers of my blog are well acquainted to the fact that I am questing and researching on a local variety of rondel knife, the "Brakkersfelders Knopmetz" of old hanse provenience. And my research up to date has made it very plausible that this steel was - amongst other places - refined at the site of our ironforge. I state that due to the research I have made in the Civil Archive of the town of Breckerfeld and the Ennepetal Ironforge Chronicle from 1592 (fragment). The Manor of Ahlhausen was the property of the Duke of Bönen, who in that period of time also was patron of the ironforge. I found the bloomery steel on an ancient trail leading from the ironforge to the manor. So I was very excited that the steel I found is most plausibly the legendary steel from which the Brakkersfelders Knopmetz was made from!

And I could not resist forging an utility blade from it to test it and its properties. As I said, the spark analysis offeres clue that there was roundabout 0,5%-0,7% carbon in it. The steel, although wrought, reacted quite nicely to the forging process, with a temperature window from 900-1100°C. It offered a strange resistance to the hammer, an indication of high ductility. In the forging process there was one layer coming off, which I rewelded in the forge using Borax as flux. It welded very nicely and evenly, even if it was done the dirty way with no grinding beforehand.

 It did not move that well under the hammer, too. Annealing after the forging process was done in 8 cycles, bringing it up to dull orange and letting it cool besides the forge and then at room temperature, which then was about 25°C. After achieving a softness that made it possible to work it with a file easily, it was ground. Forging to final shape, by the way, had been done nearly 90% beforehand, so little grinding was required. Then I did a probing quench in lard with additional tempering from the heat in the spine and some heating over the open forge, until a blue hue was achieved. This turned out to be too much, so I repeated the quench and just tempered to a golden hue. The blade appeared too soft afterwards still (testing by slamming it edge first into mild steel rods).
 So I annealed it once again, and, gathering my resolve, did a selective water quench, first with a long temper to a blue hue, then again to a golden hue.
 Afterwards the blade still dented when I slammed it into iron rods. A file was able to take off shavings, not as easily as before, but still far too easy.
Bummer, I thought, you have messed that one up and was right mad with myself for that.

48h later I tested again. Still denting on steel rods, but now it chops stag antler without denting, carves the spine of selectively tempered spring steel knives, and the file slides off with the minutest of shavings. A knife of defined 58HRC can carve the edge of the knife, but a Karesuando blade of 12C27 with an estimated hardness of 57HRC just slips off. Blimey, what´s that, I said, and tried to carve the 58HRC blades edge... and it bit. From all I can know I would estimate it to 54-56HRC, but that last feature simply is not logical. My theory is that the blade is not that hard, but makes up for what it lacks in hardness in tensile strength and ductility. The fact that it dents on iron rods but chops stag antler and carves spring steel could maybe be explained by the composite nature of wrought iron. Some areas dent, others do not. It´s not a homogenous material after all! Bending it to 15° showed no adverse effects, slamming it tip first into hardwood and levering it out bent the first millimeter of the tip, but left the knife unaffected otherwise.

Be it as it may, for a 16th century steel this would have been state of the art.

Now I have made a big fuss in the beginning of this article by saying that there was just a coincidence, and the events are not linked to each other, and from a logical point of view, this cannot be supported. But then I can say I have never searched and researched consciously for that steel. It just came to be. It just happened. Word led me from word to word, deed led me from deed to deed. It has been a fairy tale so far, and it still is. And in this fairy tale there´s another story that goes like this:

"once upon a time, in a land far away and around the next corner..."

It just happened. t occured to me. Again, and I like it. ;-)

We are told a lot of lies these days. I daresay I´ll stick to my fairy tales more from now on... ;-)

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