Metal

Hi, I'm an Iron Worker!

OK. So, most of anyone who knows me probably knows that I work in a steel mill, and that my job is some sort of fancy inspection thing where I give ultrasounds to pipe. That's not the whole story, that's not even a fraction of it, but I've learned that the only people who will ever understand what it really is, are other people who do the job. Outside of my coworker peers, I am alone in this experience. And that makes me sad, not out of loneliness, but because experiencing the triumph of the modern manufacturing process is something I believe everyone should have in their lives- especially regarding pipe in this age. Today, I'm going to talk to you about my area of expertise:

Steel.

I'm not a metallurgist, welder, or smith, but I work with their products. I know how the material works, and I know how their processes work, even if I haven't got the practiced hand or memorized knowledge to replicate it myself. You've got to be humble when you tell a welder of 30+ years that he botched it.

Why are we talking about this in a game design blog?

Let me answer that question, by asking you what you think of when someone mentions "crafting" in an RPG. Most people immediately think of a blacksmith. (Some people jump to a carpenter, alchemist, or mechanic first, but the blacksmith isn't far behind) I think this is because they often assume "crafting" means "shortcut to fancier combat gear".

The folly of crafting systems.

Have I ever mentioned how much I hate crafting systems in RPGs? I haven't written a detailed blog about this? Wow. I think about this like once a month. OK. Here goes. The main problems with crafting rules in an RPG are as follows:

• RPGs are typically built to focus on some sort of adventurous narrative experience. Crafting is the opposite of that. Being a skilled craftsman demands decades of practice, study, training, and research. In other words, while an adventurer runs out on a whim to chase adventure, the craftsman stays home to make yet another slightly better quality version of the same thing he's been making in the same shop for 20 years. That's pretty hard to reconcile with the normal flow of play.
• Crafting is time consuming, tedious, and boring. For example, I am a trained artist, specializing in dry media and drawing techniques, especially graphite, metal point, and ink. I love art and I love my artwork. But I hate drawing, in the same way that I hate mowing the lawn or washing dishes. It's a pain in the ass, but the results are worth the effort. Basically, there is nothing fun about the process of making something- it is the opposite of fun.
• Crafting is almost never focused on as a primary function of play. It is almost always an after-thought brought on by simulationist tendencies in the dev team. Eventually, someone goes "Wait, if the players can be blacksmiths, shouldn't they be able to make swords?" the answer to this should (almost) always be "Only if the game is actually about artisanal weapon smithing". (That actually sounds like a really cool premise for a non-traditional RPG...)
• Crafting is not game-balanced. I'm going to put it plainly: In real life, a craftsman with good, experienced hands and a mind for business, can put almost no material or time investment into their work, and sell the product for a fortune. For evidence, please read about Yves Klein. The man made a fortune painting sheets of blue. His most famous of those bland blue squares is worth 760,000 - 1,200,000 USD. It's just a sheet of blue canvas. So, given that product value is not equivalent to investment, and not all trades are equal, how do you balance that in game terms? These days, pussies players demand fairness balance in the form of arbitrarily stratified power advancement. Character wealth typically plays a role in that. You realistically should can't have a shortcut to golden glory in the form of a single character option, or people will call it cheating imbalanced.
• Real life craftsmanship is actually pretty hard. Naturally existing materials don't normally want to become chairs, or candelabras, or dildos. (You know, what with all that momentum, conservation of mass and energy, thermodynamics, & etc.) You have to force those materials to your will. Most trades demand more than knowledge, they demand a certain personality type. Who you are needs to mesh with the nature of the material and work. If it's a bad fit, you'll never be especially great at it. Unfortunately, things that are both difficult and subtle like this don't translate well to exciting play at the game table. Because it isn't fun.

Oh yeah, party central, right here.
Grab a hammer, let's pour our souls out into a piece of the Earth so a horse can walk in comfort.

So, given that crafting is boring , excessively difficult, and totally unfair, how can we represent this concept in play? Up until 2014, I said "You don't, because it's a stupid little niche thing that only some players care about anyways." but then 5th edition D&D came out, and I now have a new answer: "You don't, unless you plan to rip off D&D as shamelessly as possible." So, what did D&D 5e do? Basically, they codified bluebooking without calling it that. Instead, they called it what bluebooking actually is: downtime.

Bluebooking is the practice of playing a group game solo while you are away from the table and/or while your character isn't with the group. Basically, the player makes a "bluebook" which they share with the DM, and is available to the table to read if they like. The player writes what they want their character to be doing during their off-stage time, or between sessions, and the DM responds by writing the results of that activity between sessions. It's an obscure practice used mostly by OSR grognards and roleplay elitists. (Interesting that two unmixable fandoms both invented the same technique simultaneously. I guess outrageous pretension just tends to create thematic trends.)

5e codified this concept in their downtime mechanic. The DM awards player characters with "days" of downtime as if it were a currency. (When I say currency, I mean the RPG theory term, where HP and XP are types of currency as well.) Between sessions, players can "spend" days on pre-structured downtime activities, which produce various results based on how many days you spend on them. When you spend a day, you choose a quality of lifestyle that you'd like your character to live in during that time, which the DM is supposed to use to figure out what societal strata you fit in with, and you have to pay lifestyle expenses (actual game-coin) for each day spent.

This system is brilliant because it does the impossible: It allows gameplay to represent crafting without playing through craftsmanship. It removes the whole process from play entirely, but still represents and handles the process. Bloody smart is what it is.

In an effort to be simple, easy, and balanced, they have intentionally ignored any connection to actual craftsmanship, instead focusing on paying in downtime to make monetary progress toward the complete value of the crafted object. Since the most expensive lifestyle has the same value as your progress rate, which is arbitrarily fixed at 10gp per day, you will always get a discount on a crafted item unless your character is a complete fop. So not only is it efficient, it's also magically pretty close to balanced!

Unfortunately, this leads to some pretty piss-poor roleplaying when the players have absolutely no idea how things are actually made. Now, you can't blame them. Most gamers are kids, and even the greatest polymaths can't learn it all. Even so, if you're going to play a character whose whole schtick is that they are a metalworker, and you're going to run the character for a while, at least have the decency to mine wikipedia for some technical jargon!

The rest of this is just going to be me rambling about the steel manufacturing process. Read on if you have any interest in just how fucking badass humanity really is.

We made this. We do this, all around the world, every single day. And we are really, really good at it.

So what is steel?

Steel is an iron alloy containing primarily carbon as the alloying element. All metals containing iron are "ferrous" metals because that's just latin for "iron-y", which is good, because irony is already a totally different word, and we already have too much of this homophone-homonym horse shit as it is.

Steel is unique because it is possible to make an extremely wide range of physically different steel products from very small changes in the process. Other metals, such as aluminum, are more difficult to alter on a molecular level. A grade of steel  has its properties determined by the following:

Carbon Content. The more carbon in the steel, the harder it gets. Sort of. Usually. With conditions. We add carbon to iron during the smelting process by burning coal.

This is why simply "not using fossil fuels as fuel" isn't enough to stop climate change. Fossil fuels aren't just fuels, they're manufacturing materials, inherent to many industries. We don't just burn this stuff, we make stuff out of it. If you can think of a better way to get the carbon into the steel, you're a fucking genius, because we've had engineers trying to find a profitable workaround for hundreds of years, to no avail. Coal (actually coke, it's more efficient) is still the primary method of controlling carbon content in raw steel.

Not an especially detailed thing, but it covers the broad strokes.

Crystal Structure. When steel cools, its molecules form a crystalline lattice on a microscopic scale, alternating with fields of iron and carbon. These alternating crystals form in clumps, called "grains". The size of the grains of carbon and iron, and their shape, have significant impact on the final mechanical properties of the product.

Crystal structure is primarily controlled through heat treatment; raising the steel to a given temperature to let the molecules move more freely, holding at that temperature for a controlled time to let the molecules move around, then quenching at a controlled rate to form crystals of a desired size and lock the molecules in place. Different types of crystal structures sometimes have specific names as though they are different materials, such as martensite.

Additionally, we can shape the grain structure of the steel through forging, which changes what those properties are like at different places in the product. This is why forging is often favorable to casting; you can make a product that is not only hard/strong enough, but also has its strength/hardness directed at the work surface.

Hmm. Looks like the forging has some sort of non-metallic inclusion in there...

Other Alloying Elements. Of course, you can also make other types of steel alloys by mixing your base steel with some other stuff to interfere with the crystal lattice in new and interesting ways. Stainless steel contains at least 10.3% chromium, for example. (The chrome interferes with corrosion on a molecular level by filling particular voids in the lattice, and thus interfering with the movement of individual atoms, preventing them from being chemically dislodged. This also makes the metal very hard and thus fairly difficult to work with once made.)

Look, it's complicated, OK? There are huge regulation code books full of this shit.

Removal of Impurities. During the smelting process, we go through all kinds of insane effort to get rid of elements which were trapped in the metal during Earth's formation and cooling. Raw iron ores and recycled scrap are full of all kinds of useless mineral and gaseous crap that interferes with the crystallization of the steel, and creates concentrated points of tension or residual force inside the metal. Some of this stuff is poisonous as hell, too, so it often isn't enough to get it to precipitate out of the metal, you also need to make it go somewhere safe, or mix it with something that makes it safe.

When I'm inspecting steel with ultrasound, significant impurities and voids trapped in the steel (inherent defects) are one of the major things I'm looking for, along with existing failures (cracks) and process defects (insufficient weld penetration, etc.). Voids and non-metallics dramatically reduce the structural integrity, and thus the operational life span, of a steel object, and can lead to premature failure. These failures can result in thousands of dollars of property damage, environmental damage, and possibly even cost lives if the part in question was between a person and a large amount of potential energy. As a consequence, many steel products used for hazardous or essential purposes; including pipelines, aircraft components, bridge parts, boilers and pressure vessels, boat hulls, power plant piping, crane rigging, and many other things I've probably never even heard of; have international standards which codify their proper manufacturing and inspection. Most nations have laws demanding industry adhere to these standards as a minimum.

Super-duper simplified.

By standardizing all of the above properties to create a type of steel with the exact qualities needed for a given product, you can make a codified "grade" of steel that can be trademarked, patented, manufactured, and sold. This is what metallurgists do. Today, we have fancy (and pretty) charts which show the exact physical properties generated by all the different known heat treatments for a given alloy of steel.

This property, the ability to make steel suitable for so many different applications, is why it has reigned supreme as a manufacturing, industrial, and structural material for thousands of years. To get an idea of how much it matters, consider this: we weren't able to make a grade of aluminum strong enough for a truck frame until 2013. Sure, we could make very hard aluminum alloys, but strength and hardness are not the same thing.

A hard metal has very high resistance to deformation of any sort, but is also typically very brittle. That means that once you apply force beyond its deformation limit, it isn't going to bend much before it just snaps. Imagine trying to bend a granite rod.

A strong metal, conversely, has very high deformation tolerance. In stronger metals, we can more clearly see the distinction between elastic and plastic deformation. Elastic deformation is a range in which the material bends, but returns to it's original shape. Springs have very high elastic deformation tolerance. Beyond the elastic limit however, you have plastic deformation. When metal plastically reforms, the molecular structure is being shifted internally, and the steel is taking on a new shape. Plastic deformation is what we achieve when we forge metals. Imagine bending a metal bar.

Strong, but not quite strong enough against mother nature.

For a sword, you want both. You want a piece of steel that is as hard and as strong as possible, so it will almost never get damaged, and when it does get damaged, it'll just get bent or pitted rather than chipped or snapped. Unfortunately, for a very long time, it seemed as though the two were inversely correlated. The stronger the steel got, the more flexible it became, (Like how gum is soft but you can stretch it for miles) and the harder the steel got, the more brittle it became. For centuries, the forefront of metallurgy in iron and steel was driven by weapon and armor smiths looking for the right alloy and process to get just a little more hardness per strength.

Not that weapons actually snapped very often. More likely, they'd splinter or chip.
...
You know, like real tools?
...
You have used real tools before, right?

Folding your steel, like what the Japanese used to do with their katana and other similar swords, was one technique smiths invented to overcome the limitations of the material available to them. See, back in the day, we didn't know atoms were a thing, and we didn't think of smelting as chemistry, so we didn't really fully understand why iron from one place might be better or worse than the iron dug up from some other place, or why some smelting operations just made "better" steel. So, when raw iron rods arrived at the forge, they were... inconsistent. At best.

The solution was to flatten out several bars, however many you need for the product, heat them up to some ungodly temperature, and then smash them together with a hammer, forming a forge weld. Then you heat it all up and twist the structure. Then you heat it and flatten it. Then you heat it and twist it. Repeat arbitrarily. The Japanese opted for flattening it out lengthwise and folding it back on itself to create repeated forge weldings, each layered on top of one another. Do enough folds or twists, and you'll have the crap steel and good steel pretty thoroughly mixed, with roughly even properties. To be clear: folding of steel does not make it any stronger. It just spreads impurities more evenly. (And looks really pretty) If you live in a civilization with access to a Bessemer blast furnace or better, this is a lost art, and sadly, there's a good reason for it: we're just too good for that primitive crap.

A fairly elaborate forge welding being done for a decorative work.

So how does smelting work?

Smelting can be described, most simply, as melting metal out of gravel. It works, because most minerals, aside from silica and a few others, have insanely high melting temperatures, much higher than those of most metals. (This is why lava is capable of killing you by sheer radiant heat before you ever get near it; it is composed primarily of molten minerals that are well above even their own melting point.)

How did we figure all that out?!

It wasn't easy. On the scale of human history, from the time physiologically modern humans appeared, it took us over 10,000 years to do it. All of modern industry is standing on the shoulders of countless forgotten giants, lurking in our prehistoric past.

What is casting and founding?

This process is called continuous casting.
Molten steel is poured down a slide and cooled as it falls.
This thing runs as fast as the steel pours- it ain't slow.
Once solid enough, it rides on rollers.
Successive rollers shape the steel.
Somewhere down the line, a machine cuts it into billets. This is the process EVRAZ uses to make its base material.

Casting is a manufacturing process in which molten metal is poured into a mold and allowed to cool. It is... an imperfect manufacturing process. Cast iron and steel products have a random, coarse, evenly distributed grain structure that is typically not useful in any particular way beyond its generic mechanical properties. The cooling of the steel involves significant shrinkage, which puts serious restrictions on what shapes can be cast such that the steel does not become trapped in the mold or deform in ways which reduce its structural integrity.

All steel begins its career as a cast product, typically as a billet (giant flat slab) of raw steel. This initial casting is called founding, because it is all tied up with the smelting or recycling process preceding it. A foundry is a generic term for any facility that casts billets from a smelting or recycling process.

The old process was done in "heats". You'd cast a billet as a big block, and let it cool from the top. The top would experience most of the shrinkage, and is the primary point at which inclusions are accumulated. This malformed and defective top portion is cut off, leaving a clean slab from the bottom. The top is then thrown back into the start of the process, to try and extract more usable steel from it.

Most modern facilities just continuously cast the steel, as explained earlier in this article. It's faster and produces no intentionally defective portion for redundant recasting.

What is forging?

This is an industrialization age diagram of 3 forging steam hammers.
They basically still look like that, but blockier.

Forging is a process by which a cast (or sometimes partially forged) base product is shaped by force into a new shape. This process actually bends the crystal lattice with the steel, shaping and directing its mechanical properties. In this way, we can make products with high shear strength in one direction and high compressive strength in another. We can make 3-storey tall drive shafts and jet engines.

There are 2 types of forging.

Hot forging is the classical technique of heating and hammering. The strength of the metal is reduced with heat, and then restored by a quench. With a hot forging process, you can apply a heat treatment simultaneously through careful timing of the heating and quenching process.

Cold forging is just shaping cold steel with brute violence. Cold forging can broadly be categorized into machining and finishing. Finishing is the fine artisanal work done on a base piece, such as carving the threads into a bolt, or grinding out the cutting edge of a blade. Much of a jeweller's work is technically finishing, as are most of the decorative arts in metalworking, such as polishing, etching, and engraving. Meanwhile, machining is much more like carpentry, where a base piece of metal is manipulated by tools. Machining often uses more cutting and grinding techniques to remove material and make a positive from the remaining space, but they also use tools to bend, fold, upset, or squash the metal as well.

Cold forging has a significant impact on the mechanical properties of the base material. Shaping cold steel crushes the crystal lattice, creating concentrations of varying mechanical properties. This is called work-hardening, as it makes the shaped area harder, but weaker. Cold forging also has a tendency to create areas of residual stress inside the steel. If these localized stressors are exposed to cyclical loading, (repeated impacts or pressure) they will quickly reduce in structural integrity, leading to an eventual failure. As such, cold forging must be done in a careful manner, with the intention to work-harden the steel into the intended properties.

EVRAZ Red Deer Works uses a combination of hot and cold forging to make steel pipe from steel sheet. The steel comes in a giant roll, which we unwind and flatten out. Then we cold-forge it with rollers to turn it into a tube. Where the two edges meet, we heat the steel with an electrical current to nearly melting point. Finally, while still screaming hot, the roller system forces the two soft edges together, forming a forge weld. This is called Electric Resistance Welding, or ERW.

What is the difference between a furnace and a kiln, anyways?

Boy, I say, BOY, do NOT make me come over there!

I have seen this mistake made enough times to be insulted by it. The difference is primarily in the shape of the thing, but the reason behind that shape matters more. Furnaces and kilns move and concentrate heat in different ways, to suit the demands of the manufacturing process. Furnaces and kilns are used on different materials, and have different objectives, so have unique structure- they aren't even made of the same materials!

I repeat: not fun.

A furnace is designed to concentrate heat in a focused work-area on the product being worked. By definition, it must achieve this while being open to the surrounding atmosphere, so the craftsman can manipulate the fire and product during the heating process, and so the product can be periodically heated and removed for working. This means, in order to get those high temperatures, you need to focus the path the air takes through the fuel and flames, to concentrate the heat as much as possible. This is why furnaces are often tall and skinny, they're trying to squeeze that fire into a tight column. It is not just a hot box, it's a vertical wind-tunnel of flame.

Today, we actually don't use these much, because we have invented far more efficient heating systems. Even people practicing traditional blacksmithing generally only use real forges for show purposes only, while they do their real work with a heating or cutting torch to heat the metal in whatever way they want. Because such torches can be set to produce a specific, invariable temperature, and will sustain that temperature without any input of effort, a task that would take several men in ancient times can be done in half the time by one man today, even using traditional methods. Torches are instantaneous, igniting at working temperature from a single click of the striker, while furnaces of coal or wood could take hours of work to reach useful heat. A torch directs and concentrates heat exactly where the Smith wants it, and can even be picked up and placed directly on the surface of a large piece while working. It's portable, it's versatile, it's consistent, and it's easy.

Some among you may balk at this knowledge, thinking these "traditional" artisans are somehow "polluting" their trade with modern technology, but this is just an uninformed knee-jerk reaction. A trade is not its materials, components, or its product, but the abstraction between them; the task the artisan carries out to translate materials through tools to product. What most people think of when they imagine an atrisanal trade is nothing more than its cosmetics. Blacksmithing isn't a system of tools used. The tools don't matter. Blacksmithing is the hand-forging of ferrous materials by any means. Whether the Smith uses a forge or furnace; or whether his hammer is of the peening or hydraulic variety; doesn't matter to the work in its finished form. One way or another, the steel was heated and shaped by human hand, not an engineered machine press, and that's what makes the difference.

For the record: When I did this, we didn't get fire spewing out of the chimney.
We ate hot dogs and marshmallows.
These guys are crazy.

A kiln, on the other hand, is designed to achieve a specified temperature uniformly throughout its total volume, and sustain that temperature for a planned duration. It really is just a (very, very) hot box. Kilns are often made of insulatory materials, usually a form of brick or cement, because they want to hold that heat as consistently as possible. They also direct airflow, but instead of concentrating it, they try to spread it and the flames evenly, and then direct the heat from the fire evenly up and outward through evenly distributed vents. There is usually some system of racking inside a kiln, (as opposed to the open interior space of a furnace) to support the individual pieces being fired during this process. This racking is not just a haphazard grid, it is also an integral part of the air flow control system, to try and ensure the heat moves evenly around and through each individual piece. (Games with crafting systems which include pottery, that allow you to make one finished item at a time, are totally out to lunch. Individual pieces are fired in large batches, all together, all at once.) Finally, most kilns are sealed during the firing process. When I say sealed, I don't mean they close the door, I mean there is no door. They brick it shut. It becomes a fully enclosed vault of fire. Kilns that have doors are usually pretty small pre-made things that colleges and manufacturers purchase, and they're usually gas-fired. Artists, for some reason, have this absurd obsession with building their own kilns, to the point that I'd call it fetishism. (This is one of the many reasons I hated ceramics back in my colleges days.)

They are NOT the same thing. You can not fire a vase in a smith's furnace. You can not heat a sword for forging in a kiln. If you try, you will soon wreck something. There's one more misconception I'd like to clear up while we're on this topic. There are two types of furnaces.

Blast furnaces are huge.

I already explained what a forging furnace is like; a vertical wind tunnel full of fire. This type of furnace, along with the surrounding equipment necessary to make useful products from it, is called a forge. People in a forge shop generally would not refer to the furnace as a furnace, unless it was specifically damaged somehow. This is COMPLETELY DIFFERENT from a smelting furnace! A smelter is not just a fire tube or hot box; it is a complex and highly specialized machine. Modern smelters aren't just a single machine inside a building, they ARE the building. You can not simply smelt ore in a forge! You can not easily heat a steel rod for forging in a smelter! Think back to the section about how smelting works. A smelter needs to concentrate heat, achieve a specified even temperature for a specified duration, contain the liquid product during the heating process, expose the liquid product to oxygen, and all sorts of other tasks. It has multiple moving parts, and there are many variations on this system for making various steel materials.