Some 15th century arms

I've been slowly working on a pair of 15th century arms for a really charming (no, seriously, he's great) Canadian patron.  There's some nice embossing on the fan that's new to me, and the elbow is a fundamentally different design than I tend to build.  The vambraces, rerebraces, lames and hinges are pretty much my standard deal. They articulate like a dream.  I almost don't want to ship them.

Here they're just before getting annealed so I could tweak the fit and planish the vambraces.  I do some hot planishing, but with the heat of the flame I have to wear dark shaded goggles to keep from getting welder's flare, which reduces my precision a bit and forces me to work faster than I'd like.  410 is air hardening, so you can't just slowly cool it and then expect it to do you bidding while cold.  For very small changes that works OK, but most shaping after a heat will require annealing. 
  Here they are in the forge being hardened.  They're out of the tempering oven now.  They need to have the forge scale stripped off, get riveted, have the interior painted and get strapped.  This last set of steps is agonizing!

Comments

Mojo said…
That's coming along nicely!
Good work!
Anonymous said…
When you harden 410 do you simply heat the entire piece up and then let it stand in open air or do you use a fan or pressurized air to cool it quicker? After air cooling do you need to temper it or does it have a suitable hardness/ductility at that point? I have heard of acid used to remove scale from heated stainless, is that also necessary here or would normal grinding/polishing be suitable? Lastly, if using heat to roll an edge on 410, does it crack easily?
While 410 is technically an air hardening steel, and it does get harder when you just air cool it (which is a pain when you're doing hot work and then need to planish it) it doesn't get quite as hard as I want for combat, and it doesn't guarantee that it's hardened consistently. So I quench it and then temper it. If there's much oxygen in the forge when it's soaking past the critical temp point it will grow some forge scale which is curiously tough stuff. You can sand it off, but it's a ton of work, burns through your sand paper fast and heats the piece in the process which can jack with the temper. I find that using acid saves a lot of work.

When it's hot, 410 flows quite nicely. It's not brittle in that state, so I haven't managed to crack it through hot work. Too much heat in a small area can melt parts, and if you're not careful it's possible to thin a piece excessively.
Anonymous said…
Would oil be a suitable quench for a fighting hardness? How badly does it warp and if does warp, can the warp be fixed by bracing with struts during the tempering re-heat?
Oil can work fine. Some folks prefer it since it's a little gentler than water, but I don't like the amount of clean up and smoke. Unshaped pieces will tend to warp substantially. I suspect that one reason we don't generally see flat medieval armour is because of that warp during heat treating. The other reason is that it doesn't fit your body as well. For bad warps it makes more sense to either fix it while it's hot, or anneal, reshape and try again. Pieces aren't soft enough for bracing during the tempering step to help significantly. Tempering temps are usually below 700 degrees F.

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