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I Forge Iron

Orange deposit


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I’m no expert but I’ve seen some orange colored stuff on the coal in the forge right after burning coal from the stigler Oklahoma coal mine, but I’ve never seen anything transfer to the metal. Steve is likely right its probably rust though,  Do you have a picture of the orange deposit? 

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More precisely, iron oxide in the form of Fe₂O₃ (rather than the Fe₃O₄ that makes up forge scale), also known as hematite. Rust as such is a combination of hydrous iron oxide (Fe₂O₃·nHO) and iron oxide-hydroxide (FeO(OH), Fe(OH)₃).

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Note when asking such questions is is nice to tell HOW you are getting that.  Using an induction forge in an inert atmosphere is different from using a coal forge which is different from using a charcoal forge which is different from using a propane or natural gas forge. YOU know the details we don't!

Lower temps scale less rapidly than higher temps; DEPENDING on the oxidizing/reducing atmosphere of the forge.  Hematite is the red rust and Magnetite is the scale/black rust  (Magnetite can rust to hematite in a moist oxygenated environment.)

Do you use water on a coal fire or quench in water?

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Sorry I didn't get back to you guys sooner. I'm using a propane forge and I try and keep the flame neutral, but things change as it gets hotter.

I think Frosty's idea is probably close if not right. I have never seen scale rust. I've collected magnetite (fe3O4) on the beach. After a storm all the white sand washes away and the beach is nothing but black sand. If salt water won't rust it...

This stuff appears more as a deposit than a reaction. Now that I think of it, it accumulates mostly on the parts of the steel which are exposed to the flame. It's also most prevalent when the forge is heating up.

I'll keep an eye on it to more accurately note the conditions. 

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DARN, you aren't using coal! There goes my theory about palladium in that coal vein. Hmmm, maybe in the refractory in your forge? Palladium oxide is orange and if it were dissolved in the water or adhering to the surface of the pieces it'd make sense for it to form replacement deposits. 

There's also no telling what was in the scrap stream when they made the steel, I've had batches that show copper staining in some situations. 

Frosty The Lucky.

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I've watched this stuff accumulate on the scale while a piece is reheating.

I tried to scrape some off to see if it was magnetic. Unfortunately the layer is quite thin and all I got were bits of scale. I wiped some off with a towel and it was unaffected by a strong magnet. The sample was so small that it wasn't conclusive, but I couldn't get any movement at all, even on small threads that were covered in it.

I dunno. It's probably just some deposit from the propane. 

 

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It forms while the piece is heating in the forge? That sounds like you have lime/calcium in the water and a residue is oxidizing in the fire. 

Frosty The Lucky.

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