Support BladeForums! Paid memberships don't see ads! Ok so this is a bit of a lengthy project of mine, I started forging the steels for this last year, its a bit of a slow and strenuous process too, everything is basically hand forged with a 4lb or sledge when I can get a striker. still currently working on the steels but I would like to share what I have been making and get some thoughts on it, there is a few complicated details and processes so bear with me. I will use simplified terms instead of the proper Japanese terms for conversation simplicity. The blade design will be a Kobuse with a complex skin steel made from about 10 different steels; the core and tusba, drag, sheath collar ring and pommel fitting will be wrought iron I forge welded together from my last bloomery. So onto the skin steel which is the hard part. Theres not a whole lot complicated about the steels but the way in which they are formed is, there is 6 general types of steel by grain structure (going off the way the elements are formed) and how they absorb, retain, transfer and diffuse shock. The Goal is to make a steel with a complex internal structure as well as making enough of it for a 8 inch tang and 25 inch blade minimum with enough steel to preform an end cut on the tip. I will need a brick 5X3X3/8ths”. To fit a 1x3/4thsx4 Canoe shaped core. -Bloom Steel made from manganese nails with deer bone and some added nickle. This section has been folded 17 times so its relatively homogeneous at this stage, it also has undergone a process where it was thinly painted with satanite and heated to 2400 degrees for about an hour to ensure even carbon distribution. It welds remarkably well and considerably tougher then steels such as 1095 but tends to be more plastic still instead of elastic. its not going to win any awards for being bent 180 and going back to form, it stays bent instead but also doesn't shatter when it hits something like a pig bone, chips less as well. it's pretty close to .90% carbon, as for the nickle content of the deer bone its hard to say, I used an entire leg of bone and an entire lower jaw, teeth included. -Cru Forge V which has a structure similar to cpm steels in that there is relatively low elemental segregation. as well as vanadium following John Verheoven's observations of Damascus blades, this provides my vanadium carbide banding. -Iron Wire, made from my bloomery .05 thick ground to a round. This can be forged flat with a hammer cold, its pretty soft and ductile and has low slag content. (it’s basically just forge welded nails with some extra carbon) -10XX series spring steels and small amounts of 5160 -15n20 for its shock reflection (as well to supplement the low amount of remaining bloom steel. -W2 for its stability So the form is as follows, I have made sections of steel starting with a 2 inch tall stack a inch wide by 4-6 inches long. This is about the limitations of my ability to forge weld with a 4lb, it takes me about 15 hours to convert this into a solid welded billet 3/8ths thick an inch and a half wide by about 8 inches long. I took the time to heat, reheat, flux, weld, reheat, flux, weld repeating about 5 times for 10 heats before drawing. Any time I had a delam I would split the weld open flux it and scrub it out, add iron wire into the area seal and restart, so each section had about 13-20 heats before drawing to ensure my quality, the ends were also hot cut off to form a seal. 1 section W2, Cru Forge V with the outsides beign 15n20 to ensure welding, 9 layers. 1 section Cru forge v and 15n20, 12 layers. 1 section Bloom steel 1 section mixed from lots of smaller chunks of piled steel, 15n20,Cru Forge V,1085,5160,1045, 40 layers thick, alternating carbon content as well as chrome to non chrome as well as iron strips in non similar locations bewteen each layer, at odd angles. 15n20 on the outside and between for welding. The bars will be thinned on the ends and formed into hooks, the hooks will be interlocked then I will use a spring swage to compress the center, repeating on either side and then forged flat, I will not work the sides but just mash it, slowly to ensure the weld and prevent the issue of a slip plane, keeping the order listed above. Once the long bar is assembled I will hot cut with an axe and fold the end of the steel a half inch and then on the second fold and every fold after I will insert the iron wire cold against the fold line and then seal it by completing the fold. I will continue to fold the steel beveling the bar down to match the widened folded section as I fold it up as it gets wider I will add quarter inch or wider sections of 1075 steel shim (.005 thick) with the edges sharpened. In principle the inserts will be reheated and welded with each further fold. Once the block is rolled up it will be drawn and the process restarted. Figuring it might have 300 layers each fold might bring it up to 5000 layers at the end of the second time the billet is folded up. I might fold it 6 more times depending on how much steel I have and how close I am to the goal, I may have to forge cru forge V down to wire size and do inserts if I have to to increase my mass. In theory since the inserts are always against the fold and the folds are on the outside, the ends of the U which form the spine will have more iron and spring steel wheras the blade section will have more high carbon steel content but still have micro layers of softer material inside, this folding process will also greatly reduce carbon diffusion because of the method the bars are assembled and folded together, as well there will be quite a bit of variance forming waves of differential. This method of folding should cause quite a bit of curvature in different directions and angles making wave patterns. With the higher layer content grinding of the edge will expose quite a bit of the content, as well the normal steel being on the spine section will aid in forming a hamon. Thoughts?