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This weekend, a friend and I attempted to produce crucible steel for the first time. It's something we've both been keen to try for a while so a couple weeks back we decided we'd put a plan together. We were confident we could build the foundry but I wasn't sure my forge burner would be able to produce the heat required. We both have the same burner and they're sort of modular and could be easily transferred from a forge to a foundry so we figured why not use two burners and see how that goes. We set out expectations at a realistic level and decided that this attempt would be to see if we could even melt steel. We filled our crucible with cast iron (donated from resurfaced brake rotors) and small pieces of mild steel to bring the iron ratio up. The cast iron content was an unknown but we worked on the assumption of 2% carbon, aiming for a final level of 1.3%, though it could end up higher. Total mass was 600g. Green glass was put on top. Once it went in we were both surprised how quickly the glass melted. The crucible stayed in the foundry for a little over an hour before we killed the fuel supply and dropped in a little Aluminium. We left it sitting in the foundry for a few more minutes the took it out to cool. An hour later the glass was cracked open and little puck fell out. It looked a little porous too it untrained eyes but we were still really happy we had seemingly pulled it off. High-fives were had. I cut it in half to reveal what looked like a mostly solid puck but a quick polish and etch revealed that there were a couple pieces of unmelted mild steel in the bottom. Despite that we were pretty pleased with ourselves. So we attempted melt number two. This didn't go nearly as well. Melt #2 was 900g of small bits from oroshigane smelts. After 80-minutes only the glass had melted. Here's what I think happened: The first run had depleted our gas bottles somewhat so at the second run our 9kg gas bottles were low and quickly freezing, dropping gas pressure and heat. Essentially we just weren't as hot the second time around. That, and powdered cast iron probably melts a lot easier than chunks of carbon steel. So in the end we determined we need a hotter fire source. LPG is expensive and will always have the freezing issue so well be exploring a waste oil burner for future attempts. When we've established a system that will reliably melt steel we'll begin looking closer at our recipes. All in all, we're pretty happy with the mornings work. All feedback welcome A.J. Prime *Edit* Photo seem to have published in the wrong order
I daydream alot, and the past months the dreams have been dominated with crucible steel. I have plans to give it a try this summer, but I'm also thinking about improvements. This question is about one of these future improvements. For starters I'm gonna let the ingot cool in the crucible. But every video I've seen with this approach has given large dendritic structures, which might be desirable for Wootz, but I don't want 'em. I saw Ric Furrer in the Ulfberth documentary, and although I don't think the word Wootz was mentioned, the steel sort of behaved like I've heard Wootz would, in that you have to "nudge" it gently initially. So the plan eventually is to make a pour. Also this could give a more suitable size and shape for forging. Could someone point me in the direction of some litterature on the topic, containing some info on cooling rates vs. dendrites and also segregation?
I've been asking myself what I would use to up the Ni in crucible steel if I wanted to make my own high contrast crucible steel damascus. I'd like something high in Nickel, and low in everything else, so I was looking at SAE 2515. In what kind of applications would this be found as scrap? Roller bearings? Other suggestions? I doubt I can find any FeNi or pure Ni locally. And I haven't been struck by any meteorites lately. We are the knights who say Ni!
so since I am on holiday I started a redo on my wootzsmelter, after working in the garden. It is my old smelter, made from an 11kg gasbottle, following a design I got from Achim Wirtz here in Germany it was a bit "nifty" as Niko once said, very narrow for an A1 crucible, so I want it to be bigger in the "heatroom" which should give me less trouble with the heat for the melts for that I took out some of the casting - had to hammer it out with some effort - finding that I made the walling very thick, some pieces where thicker than three - four centimeters out came over 11kg, much more than I thought the wool is still in good shape, so that can stay, the bottom is still ok and the pipe gives a tangential flame to the bottom of the crucible, there is anough space to use some stands, too I found an old bottle that will make for the inside, it is big enough to give the space for my crucibles (Achim said: a double-magnum redwine bottle will do the trick, too) more in the next days