DanielC

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  1. An increase in carbon with the lack of most other carbides lends to edge stability. A 1.2 or 1.3% C edge can be slightly thinner at the same hardness as 1095, which is why these types of steels exist. White and blue paper and various german file steels rely on these slight metallurgical differences to squeeze out as much as you can from steel for high end cutting edges. It is also important to not that these steels were designed for this specific purpose, as opposed to being an alloy we use that was first developed with a different application in mind, like 52100 for example, which is arguably one of the best western steels used in cutlery. As far as the cementation process, yes it can be done. It depends on time and temp. You may even have some neat banding in the end.
  2. Yep, my spelling was off unfortunately. Ledeburite. I have quite a variety of gray cast I've made on accident that formed in different structures depending on rate if cooling.
  3. Perhaps similar. I am not sure the mechanical properties dendritic cementite are the same for graphite in needle form, but maybe. The two processes impart similar properties to the elasticity of the metal, so maybe. With cast irons you have a very high concentration of cementite in the form of ludabrite, and if Si levels are high enough (1-3%), it doesnt allow carbon into solution and precipitates graphite needles. Depending on heating conditions these needles can be in primary cementite or not. The carbon content will also dictate this as well, as you go above 4% or roundabouts regardless of Si content. I've always imagined graphite being pockets of porosity among the hard ceramic ludabrite, and then becoming stress risers during a cold bend, rendering a snap. I assumed this is why white cast iron is both forgeable and is more durable. These are my assumptions though as I dont dive too deeply into cast irons except during the occassions that I make them, see them in the scope and read about them in literature. Also, this material is a little different than general steels. Imagine a sea of pearlite (or martensite if its hardened) with very hard ceramic waves (cementite). This material gave swords the ability to be knife hard, and not snap when bent. It also gives a lot of edge retention and stability.
  4. Gwen I dont. I would consider it slow, but not the slowest I've ever heard. I cut back the juice for about 10min andnthen fully shut down, closing all entry points and letting it cool off in the furnace. A slow cool enhances cluster sheet spacing among the dendrites, and the final pattern is partly a result to this. Too slow and yes, pockets of CO2 form and could possibly be filled with precipitated graphite which will in turn wreck a pattern and create cold shut streamers containing graphite. Tbh, that attempt was a little different than my usual and did not incorporate a means of burning any O2 in the steel as it was liquid. I tried using CaC as an oxidizer instead, but it seems to have failed me. I feel like this is a result of that, but I could be wrong. A good way to check later on is to use my ruler for microscopy and measure the distance between aligned bands. If they are wider than 80 or so microns then it's probably a result of too slow of a cool. There is a fix to this however, and it is employed early on. The ingot is quite large, and there are narrow crucibles available, however the more cycles ran and the more distance forged, the better things get. Ohio Thats a good documentary. I also use beer bottles. Preferably green. I had to stomach Heineken over the weekend for this last run. I use commonly sourced graphite/clay crucibles. These are #3's, but I'm thinking about stepping up to #4s
  5. And after a roast, I have what appears to be in the upper atmosphere. ~1.7% C
  6. This is what I do when I encounter failures in steel making. I always, always, always pick myself back up and keep going. New 5.5 pound puck, it is in the kiln roasting right now and the resulting metallographic structure will tell me more about carbon content, but according to estimations it can be 1.4% C at the lowest, and 1.7%C at the highest. Broke the 1st use crucible though, oh well.
  7. So found out there was a void in the center of the puck which led to a long cold shut. I decided to skip "killing" the melt this previous time with my go to method and instead tried to use Calcium Carbonate. Apparently not enough. Sucks, but its part of the game. 18 hours of forging under the powerhammer, 80# of propane tons figure it out though. I had just finished coarsening the cementite and started to stretch it out too. Oh well. Time for a new melt tonight. An old puck and some chunks of this recently worked bar. Should get me around 1.6-1.7% C.
  8. Hmm hard to tell. Years of conversations with various people.
  9. Ah thought you were talking to me because you did send me a pm and I'm not sure if I responded.
  10. Apologies SLAG, I'm in and out. Very busy. I will get back to you on it soon.
  11. Social media is a beautiful thing. Ann, Ric and pretty much the whole community talk, argue and present data, arguments for or against and examples all the time. The best wootz maker in the world resides in Finland, and it is his methods that I borrow from through a friend who took a class with him. Tbh, thanks to social media I am close friends with most of the steelmaking giants. Both professionally and personally. I am even friends with one of Al's students and friend and he helps me make heads or tails of some things.
  12. Most of us just use the term Wootz because it is shorter, and most have realized that the only thing differentiating between modern crucible steels and historic wootz is the melting process, getting the alloying agents in the billet to form a good pattern. However I typically reserve the term for the better patterns and not the inferior ones I've seen produced by several as of late. The patterns often associated with historic wootz are obtained irrespective of melting procedure A pattern in the end is dictated by chemistry, melting temp/time, time of solidification, roasting, forging procedure and heat treatment. There are many forms of crucible steel out there that wildly change one of those key things to form a different pattern, such as bulat. Modern purveyors of crucible steel have finally gone a little further than Pendray, and the field is getting smarter by the day.
  13. I have it stored in my phone. Her opinion diverges from Verhoeven. It's difficult to make heads or tails out of who may be right, except for the fact that she doesnt make or forge crucible steel and Verhoeven worked closely with Pendray who did.
  14. Thanks. Given that it did water, the carbon content was indeed 1.3ish. Even with a power hammer, crucible steel is rough. Easy, easy, easy to mess up. Really hard to sync everything together just right. It was indeed crucible steel and Ric Furrers special that got me into smithing period. The pattern will become more bold and pronounced the further I go as long as i dont screw it up. As of right now that etched section is still over an inch thick. The pattern gets better as you gradually get closer to blade thickness.
  15. Was on the verge of chucking this bar today because it was not looking good under the scope. Decarb from the soak may have left a carbon content gradient that needed to be ground through revealing the true nature. As can be seen in the picture below. The amount of spheroidized cementite looks very low in concentration to be 1.3-1.4% to me. This took roughly 6 hours to turn into a short oblong bar. This is the picture (directly below) that made me feel like there just wasnt enough cementite. So here I am today, about to give up on the bar. Assuming I either cooked all the carbon out in the roasting by not protecting the Ingot well enough or I overestimated carbon content. Either way, after another 3-4 hours of forging, I felt the bar finally give under the hammer and feel like a beautiful piece of steel and not a hunk of cast iron. The watering pattern at the edge gave me a sigh of relief. Whew. Lucky me, the bar weighs over 4 pounds. Lots of blades if all remains well.