Join Date: Mar 2005
Glass in the Crucible
According to Föll, all true crucible steel has a high carbon content because the alloy must be at least eutectoid in order to become liquid at the furnace temperatures of the time. If it had no affect on the function of the blade, the SI content is irrelevant. Remember, the people that made this steel and forged these blades had no concept of modern metallurgy. If the SI didn't break it, they weren't about to fix it.
In her doctoral desertation (Crucible Steel in Central Asia: Production, Use and Origins), Dr Anna Feuerbach mentions a ring of glassious material inside the crucibles. If I recall correctly, Nonikashvili says that finding was the reason for his experiment. I wonder, however, about the possibility of any glassious material sticking to the steel of the ingot and being incorporated into the blade during forging. Even under low forging temperatures, that material should become liquid and run off the steel right away, no? I think that any SI content in the steel would be in the form of an alloy precipitate as the crucible charge cools. I am more than a bit unclear about this but, it appears from what I have read of Föll's monograph, it is the way in which the precipitates (C, SI, P, etc) are manipulated during forging that governs the strength/durability of the blade.