Riddle of Valyrian Steel part 2 – Damascus

A little while ago I joined the American Chemical Society in making a video about Valyrian steel with and overlong companion piece here on the blog. There was some complaint that I had ignored an obvious contender when discussing possible materials, though: Damascus steel.

It was a conscious decision to skip over Damascus steel in the original article. Not because it wasn’t worth talking about, though, but because it was too complicated. It is a mess of metalurgy, lost history, and experimentation. A four minute video doesn’t have a lot of room for nuance. With a bit of time and a fair bit of digital ink, I hope to patch up that hole, though.

First, let’s define it. What is Damascus steel?

Damascus Steel can refer to:

1. Steel produced or sold in the Damascus region of what is currently Syria from before the fall of the Roman Empire to the early European Renaissance.

2. Blades made in the Damascus region from Wootz steel imported from Southern India during that period.

3. Blades produced in modern times which replicate the properties of the above.

This is already a mess. Damascus steel can mean different things to different people in different contexts. Even if we narrow it down to our second definition, which I intend to do, we’re talking about a fifteen hundred year history. Over that time, materials, techniques, and craftsmen changed and evolved. Damascus steel isn’t one single thing.

The reason Damascus steel stopped being produced around three hundred years ago is unclear. Either the source mines ran out, the source of fuel for the smelting furnaces became unavailable, European invaders interfered in the production, or developments in the field replaced the process. Most likely its a combination of all of these factors.

Whenever you look up Damascus steel, you will find claims that the technique for making it was lost, frequently with claims that it’s better than the best steel we can make now. It is true that the process was lost. Steel production at that time was a combination of oral tradition, trade secret and superstition. Nobody wrote it down, and even if they had, the process wouldn’t have been replicable as it would have relied on specific ore, fuel, and environmental conditions that may not even exist anymore.

So it’s not that the secret to making Damascus steel is something that we don’t know, it’s something that we can’t know. Recreating it is like trying to make your great gandmother’s apple pie without a recipe. Even if you do get it exactly right, you can’t know that you did. You won’t know which apples she used, how hot the oven was for how long, or whether your crust is appropriately flaky.

Unlike your ancestral apple pie, we still have existing examples of Damascus steel. That is only somewhat helpful, though. The finest examples of the material happens to be contained in valuable artifacts. Most collectors and museums are rather opposed to drilling holes in their relics to find out what they’re made of. Also, like apple pie, 300 year old steel is not quite the same as it was fresh out of the oven.

There have been a few opportunities to analyze the composition of Damascus steel, though. In 1924 an explorer acquired and then sacrificed some blades for study. At the time the results showed a very high carbon steel, the sort that would normally shatter very easily, but with some other alloying elements, namely silicone and phosphorus which mitigated that effect. They also analyzed the crystal structure and found that the dark swirls were bands of cementite, a very hard, high carbon iron crystal.

More recent analyses have found that the composition of the metal was somewhat more complicated than that, with over a dozen alloying elements each contributing their own part to the final properties. Even more recent studies have found that at least some Damascus blades have carbon nanotubes embedded in them, further increasing their strength

Beyond it’s composition, forging and heat treating Damascus steel is no small feat. It has a very narrow range of temperatures in which the metal can be worked, and creating the dark swirling patterns on it requires slow and carefully controlled heating, cooling, and tempering cycles, along with careful polishing practices.

Now we know what Damascus steel is, but is it a good match for Valyrian steel? Well, yes and no.

It is unusually high quality steel for the period in which it was being produced, and it does have the distinctive dark swirls described by Mr. Martin as the marker for Valyrian steel. The big stopping point, though, is its reaction to heat.

Valyrian steel is supposed to be nearly impervious to heat and can sit through a raging inferno without losing any of its properties. Damascus steel, though, is very susceptible to high temperatures. High temperatures will dissolve the structures that give it the rippled effect and it will become either too brittle, or too soft to be of any use in a sword.