Hey guys, a few questions about metallurgy.

1. what is difference between high carbon steel and mild steel?

2. Which is more historically accurate?

3. Was iron or steel more common for armor?

4. What is "cast iron"?

5. Is there any other kind of metal that I should know about in european arms and armor?

1. The more carbon a steel contains the harder it is, but also more brittle. Since the carbon content of mild steel is quite low it is soft and tends to bend rather than break.

2. None. Modern steel contains a lot of additives to achieve certain characteristics.

3. At which time?

4. Simply iron that is cast like you would do with bronze. Maybe you have seen a documentation about how church bells are cast...
Cast iron is often used in ovens and the like.

5.Bronze, brass and copper deserve some attention. ;)

Hope this helps a little bit.

Greetings from Kiel

To expand on Arne's answere, cast iron contains more than 2% carbon and is too brittle to forge and must be cast to shape. That's the technical answere.

Would cast iron ever be used in medieval armor?

As to Arne:

If you could tell me at what periods what kinds of metals were prevelant in armor that would be great.

I can't see how cast iron would have been used for armor itself, although it may have been used for anvils or other tooling. As stated before it is brittle, unmalleable and cannot be forged. Once cast its shape can only be changed by stock removal or by re-casting.

I am really no specialist for armor. I believe that towards the end of the late middle ages softer iron was replaced by steel as the preferred material. Many things play a role in changes like that, not just the materials change, also the production methods.
With a little browsing on myArmoury you should find a couple of interesting threads to read.
Under the link "Books" myArmoury provides some interesting reading suggestions you might want to pick up.

But its late (almost 1 AM) and my english is getting sloppy. So, i better call it a day. ;)

Hi Mattjew- The dates matter alot here, as western europe inventeted the blast furnace arond 900, making possible the mass prodiction of high carbon steel. They also had tempering and later quench hardening of steel, as well as old-fashoned hammer-hardening.The never stopped using brass and bronze for furniture though, scabbard mouths quillons,pommels,chapes,buckles,and so on as it's heavier and easier to work.