Secrets of the Viking Sword

mgysgthath said:
I was curious about how brittle dendritic steel is during the first stages of drawing.. if you heat it to forge welding heat, is it still going to crack if say you squashed it in a press or used a high power hammer, or just belted the crap out of it by hand?
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Dendrites form as the highest melting point fractions solidify first pushing the lower melting point fractions ahead of the solidified portions and segregating them out. A dendritic structure is very brittle, additionally, heating it to welding heat will allow the lowest liquidus fractions to melt and run out (Ric called it "Wootz Juice") when the highest carbon concentration (therefore the lowest melting point) portions literally run out leaving a carbon poor mostly iron dendritic sponge behind. Any as-cast structure is going to be problematic. Another poster asked about letting the crucible cool slowly VS breaking it off quickly, when you are looking for a segregated macrostructure (wootz) you cool it very slowly and then never approach solvus as that would dissolve your macrostructure, when you are looking for a homogenous structure as they were in this case, you air cool the ingot as soon as possible to arrest growth.

-Page
 
sunshadow said:
Dendrites form as the highest melting point fractions solidify first pushing the lower melting point fractions ahead of the solidified portions and segregating them out. A dendritic structure is very brittle, additionally, heating it to welding heat will allow the lowest liquidus fractions to melt and run out (Ric called it "Wootz Juice") when the highest carbon concentration (therefore the lowest melting point) portions literally run out leaving a carbon poor mostly iron dendritic sponge behind. Any as-cast structure is going to be problematic. Another poster asked about letting the crucible cool slowly VS breaking it off quickly, when you are looking for a segregated macrostructure (wootz) you cool it very slowly and then never approach solvus as that would dissolve your macrostructure, when you are looking for a homogenous structure as they were in this case, you air cool the ingot as soon as possible to arrest growth.

-Page
Click to expand...

Thanks Page, that helped a lot! That is pretty cool actually.. I really want to make some someday. "Wootz Juice" I like that ;) That will anchor it in memory I think.
 
When you overheat your steel in the forge and there is a little rivulet of molten material that explodes in a shower of white sparklers leaving behind curious fissures resembling an aerial photo of the Norwegian coastline it is the same thing, you have hit liquidus for your highest carbon fraction and it has melted and run out

-Page
 
Interesting. I've done that once, although I even overshot that and saw sparks flying in my coal forge.. by the time I jumped over and pulled the knife out it was a blade which no longer had a tang. Very disheartening, but also kinda cool (hot?). Otherwise I see that when forge welding, but that's mostly the flux flying off I think. Topics like this make me want to learn more about metallurgy. I hope to know half of what you guys do someday.
 
Just finished watching on the DVR... Very cool stuff. Like most of the rest of you, I was disappointed that it didn't show more of the smithing process (they didn't even show the construction of the handle! haha), and I could have done without the fight scenes and other "time fillers". I did appreciate the explanation of geometry and purpose of design though, and even the guy seen using the swords.
 
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