Iron Metallurgy (continued)
by Alex Cecil

Figure 3: A modern day iron production plant

Unfortunately though, iron ore is much harder to process than other elements such as copper.  The iron ore is first smelted at a high heat to produce a blob of fused stone called a bloom.  The bloom contains the treasure: small pockets of iron that can be extracted using two common tactics.

 

The two main types of iron are cast-iron and wrought iron.  Cast iron contains as much as 5% carbon, and is consequently very hard and brittle.  It seems to be a good choice for weapons, and possibly for construction when used with steel. 

 

Wrought iron on the other hand is malleable and easily worked.  It's lack of carbon is what makes it easier to work, and is likely what the colonists will have to use until the processing techniques described in this report are perfected on Arda.

 

Galvanized iron, however, provides rust resistant coating that could prove very practical for building boat hulls, roofs, and other structures that frequently come in contact with water.  We'll use zinc coating to rustproof the iron, and we would have a great outdoor alternative to steel.  Furthermore, galvanized iron is malleable and workable, allowing the colony to begin shaping it early on, without the benefit of highly advanced tools.

 

Lastly (and fittingly so because it requires so many different components to make), is tool steel.  Tool steel is comprised of iron, carbon, vanadium, chromium, tungsten, and molybdenum.  While extremely brittle, tool steel is a favorite for metal cutting tools such as drill bits because it is very hard.

Figure 4: A sheet of tool steel

The first tactic, and most likely the tactic of choice for the Arda colonists is to heat and reheat the bloom while hammering it.  This forces the slag out and from there the iron can be molded into the doft wrought-iron that promises to be a staple of the early years on Arda.

Figure 5: Workers shaping a bloom

The second tactic, however, produces the truly better iron.  By heating with charcoal and hammering the bloom continuously throughout the heating process you can work the slag into the shape you want.  Then, submerge the iron slag in water and the end result is iron harder than bronze, an alloy.  This process would be ideal because it does not require copper, which bronze does, and also would only be putting off charcoal fumes, which are easier on the environment surrounding the manufacturing plant.