Today, we know that iron with less than about 0.1% carbon is wrought iron, with more than 2.1% it is cast iron
But earlier these were described as different methods of shaping the iron, with wrought iron coming out of the furnace solid and being beaten into shape and cast iron coming out liquid and being moulded.
Is it that these processes (typically?) result in these quantities of carbon?
It’s more the other way around: Iron with more than ~2.1% carbon is brittle, and therefore it cannot be worked with tools; it can only be cast—so it’s called “cast iron”. The low-carbon iron can be worked with tools, hence “wrought”.
It’s the smelting process that results in the carbon content: smelting at temperatures high enough to melt the iron, also causes it to undergo a phase change that causes it to absorb more carbon.
Note of confusion:
But earlier these were described as different methods of shaping the iron, with wrought iron coming out of the furnace solid and being beaten into shape and cast iron coming out liquid and being moulded.
Is it that these processes (typically?) result in these quantities of carbon?
It’s more the other way around: Iron with more than ~2.1% carbon is brittle, and therefore it cannot be worked with tools; it can only be cast—so it’s called “cast iron”. The low-carbon iron can be worked with tools, hence “wrought”.
It’s the smelting process that results in the carbon content: smelting at temperatures high enough to melt the iron, also causes it to undergo a phase change that causes it to absorb more carbon.