How would fantasy dwarves produce steel?

Question

I'm designing a computer game in a fantasy setting with dwarves who need to produce steel. This is a very traditional Tolkein-esque fantasy world at a relatively "middle ages" level of technology (no gunpowder for example).

Detailed production chains are a big focus so I'm trying to keep things somewhat realistic (Is "hard fantasy" a thing?) and trying to design how dwarves (masters of working with stone and metal) would produce steel in this setting.

I think it's not too far-fetched to think that Huntsman's production of crucible steel in the 18th century could have been employed in a less technologically advanced society in the real world, if the knowledge was there.

So far I have the process as something like:

• Mine iron ore from the mountain
• Possibly need to grind this down and roast it
• Produce fuel by turning coal into coke or wood into charcoal
• Produce some kind of iron - this is the part I'm unsure of
• Place the iron along with a flux in heated crucibles to produce steel

I'm not sure exactly how the iron production, the key step to a smith, should go. Is direct reduction of the iron ore into "sponge iron" acceptable for use in this scenario, or would it need to be worked into wrought iron for use in this method? I guess sponge iron/a bloom of iron would contain too many impurities to use?

Is there a better method I should be using? Some way that dwarves in this setting could avoid the labor-intensive working of iron into wrought iron? I'm aware of wootz/Damascus steel but I think it would be nice to have dwarves use the (more advanced?) crucible method to produce larger quantities than the medieval-level humans do in the same setting, is possible. Assume that the dwarves have a fairly large workforce of willing blacksmiths, as well as the ability to use waterwheels or windmills where appropriate.

Answer 1

Why not go full out and have them use blast furnaces and the bessemer process?

Blast furnace This will get you iron. Blast furnaces were first invented in china in the first century, construction wise they are fairly simple. The biggest issue needed for a blast furnace is a powerful bellows which would naturally progress from engineering focused dwarves trying to get hotter and hotter flames or just trying to get fresh air into a subterranean city. It could even be an accidental discovery, to keep fires going underground without suffocating they will have to know how to reliably move air around. I can almost imagine dwarves cutting the furnace out of solid rock so it will last forever. Blast furnaces are still used today.

You also need limestone flux and coal but again... dwarves. If anything they will start with a much better footing as mining is far more common for dwarves and the ability to extract the necessary rocks will be easier for them. Blast furnaces are fiddly but in the exact way dwarves would love; precisions mixing, close observation, and assessment of material quality. It also requires a big collective effort, which is perfect for dwarves.

Bonus the slag from making coke from coal can be used as fertilizer and dwarven agriculture needs all the help it can get.

The bessemer process. This step is more optional and individual dwarves could still make smaller furnaces. The bessemer process if used to mass produce steel from pig iron. It will make dwarven steel consistently better and as a subterranean race they will start with a better understanding of forced air processes necessary. In the early days the process was regulated just by looking at the fire, no fancy sensors necessary. It also favors coal as a fuel source over charcoal, which requires a lot of lumber, so again better for subterranean dwarves. Even the Spiegeleisen needed to make the best steels is just a matter of mixing iron ore and certain rocks together in a blast furnace.

The only thing you really need is precise metalworking and stone cutting, which dwarves are supposed to be good at, and a small amount of metallurgy(chemistry) that they would likely have discovered anyway.

Using a limestone or dolomite instead of clay lining for the furnace will result in a better product and stoneworking dwarves would certainly notice this. It has the bonus feature of producing fertilizer usable slag, which might explain how dwarves are able to grow so much with so little farmland.

Answer 2

The dwarfs best smelters use steam distillation of iron to make the best steel. They find certain magma flows that have a higher temp than the evaporation temperature of iron (iorn boiling point 5,184°F,2,862°C). This might be a bit of a factual stretch, since most high upper strata magma temps top out around 2,000°C but if they can figure out the fundamentals of heat transfer they could pump up the temperature of one stream of magma.

They have stone tubes that guide the iron steam and it slowly condenses into liquid iron as it cools. They then add the elements they need to get the carbon into the iron. They cool it and are good to go.

Simply using magma as a heat source to melt iron in minutes instead of hours or days makes dwarfs more efficient than surface dwellers.

Answer 3

I'm no expert, but i'll give it a try. As far as i know you mostly need know-how to make steel from iron.

To make iron you smelt iron-ore and then separate iron and slag (that's were the flux is used).

Afterwards one can convert the iron to steel by using know-how, fuel and a special oven: puddling

Personally i think its far more "realistic" that a race like dwarves have a natural connection to stones and metal to have instinctual knowledge the humans needed centuries to discover.