An Unreliable History of Steelmaking
Created | Updated Jan 28, 2002
Prehistory
As far as anyone knows, Mankind discovered how to smelt iron a little before 2000 BC. At least it wasn't until about then that he finally bothered to leave any real evidence of his enterprise. Up till that time, bronze had won the coveted World's Best Manufacturing Metal title for about three thousand years running. Not that there was much competition. Among the metals then known, only bronze could take a honed edge and a light temper, but there was no recipe that could make it both keen and tough. A couple of hearty hacks to the bone with your typical bronze sword and you'd reduced it to a tastefully-decorated club. Either that or it got too brittle, and you ran the risk of leaving most of your weapon stuck in the other contestant.
Maybe someone back then decided that bronze was only ever going to be good enough for poncey Greek shaving-tackle, and set out to make a manly alternative. The metals industry always has been singularly bloody-minded. Back in the Iron Age, the first production process went like this :
- Discover how to make charcoal first
- Find some likely-looking reddish rocks
- Choose a nice day, and a location not too close to valuable property
- Mix the rocks and charcoal together in the middle of a suitable pile of other rocks
- Set fire to it all
- Wait until you notice some spongy-looking glowing stuff
- Beat hell out of this, being careful not to burn yourself
If you follow this recipe, you will be rewarded with a fairly insignificant quantity of wrought iron, plus some slag and a certain amount of clinker. (The by-products will come in handy when you later discover roads, except that it's going to be a very short road, unless and until you dream up a better process).
The history of volume steelmaking took a bit longer to get going. In fact the whole story, as we'll see, is a quest for a means of making enough of the stuff. For a few thousand years, wrought iron was great for swords and ploughshares, according to the prevailing mood, but the Industrial Revolution was going to have to wait.
The only real advance that took place between the wishy-washy general history books and the hard-nosed and boring industry-specific ones, is that after a couple of dozen generations of iron-makers they managed to boost the temperature somewhat. This meant that the iron now flowed out of the furnace as a liquid, so that it would run into moulds. The little pockets off the main runner look rather like a farrow suckling at a monstrous sow (at least they do if you've ever seen a litter of brilliant orange piglets that hurt your eyes). This new technology doesn't just stop at 'pig-iron', though. Iron-foundries soon begin to appear, using more elaborately-shaped moulds to fashion different objects. For the next couple of hundred years or so, most of these objects tend to fall apart if they get a sharp knock. We're still not quite there, are we, chaps?
The Eighteenth Century
By about 1700, most of the iron in the known world was being made in Europe. It was then that somebody noticed that we seemed to be running short of trees.
OK, to be slightly more accurate, there were other parts of the world that were making iron too, only Europe ignored them. Any country that had iron could put up a fight. This made them unsuitable trading partners on the then-fashionable European model, and so they deserved to be ignored.
Anyway, in treeless Shropshire a guy named Abraham Darby started experimenting with iron made with coal. He found that it was an excellent process for making industrial quantities of shrapnel. Then he heard that some brewers were roasting their malt using coke, which got round the problem of tainting it with sulphur. Over a pint that tasted much better than the one he'd had the week before, Abe began to ponder the possibility that the sulphur in coal was spoiling his iron too.
Cast iron now became a lot more durable, and you could of course get better properties still by hot-working the stuff. A basic manufacturing concept of casting to approximate size followed by forging to shape became commonplace. Wrought iron produced from coke was a big success, and the transformation of Coalbrookdale into the cradle of modern industry was spectacular, if a little environmentally irresponsible. To show the world the potential of abundant iron, an iron bridge was built at Ironbridge, a particularly apt choice of location.
Very soon, England's green and pleasant land was dotted with dark satanic mills, and proto-economists gave their permission for the Industrial Revolution to get started. Nothing too ambitious yet, mind. A volume process for refining blast furnace iron was needed, because beating hell out of this much cast iron was proving to be a bit tiring.
Enter Henry Cort, who was almost certainly from Northamptonshire. 1. Henry developed a secondary ironmaking process called puddling. The idea behind puddling sounds ridiculous to the layman; basically you get carbon in your iron when you reduce the ore with Darby's coke, and now you have to get most of it out again. This is a subtle concept which is quite lost on non-metallurgists. Since being a non-metallurgist is a perfectly acceptable condition which befalls most normal people, it suffices to say that puddling involved a kind of conscientious poking rather than swinging big hammers. As a result, it Cort on famously.2
Next came a Doncaster clock-maker called Benjamin Huntsman. It's a pity that it took a group of statues in a shopping mall near to his adopted home of Sheffield before anyone realised who he was. But even if the man himself was somewhat anonymous, Huntsman's legacy was noticed all right. He developed the crucible process for making steel, and it stood Sheffield in good stead for a couple of centuries, as those big bronze buggers at Meadowhall will testify.
And for the first time this was steel, with the non-ferrous bits in solution, and not strung out through the stuff like some kind of heavy-duty Shredded Wheat. The Little Mesters3 began to learn some subtle smelting and alloying techniques, and the deliberate targeting of a spectrum of properties from high strength to high workability became possible.
The Nineteenth Century
Designer Steel had been born. Unfortunately it was more Gucci than Ralph Lauren, seriously expensive and scarce. There was still no volume process for the really good stuff. Clocksprings had been added to the swords and ploughshares, but the discerning entrepreneur of the early nineteenth century was already looking for boiler-plate and battleships, and it was frankly a bit of a struggle to keep him supplied.
The next and greatest name deserves a lot more credit than the world gives him. You can forget the theory that the railways and steam power were the foundations of the Industrial Revolution proper. Without the Ironmasters, there simply weren't going to be any steam engines or tracks. And until this guy came along, the whole enterprise was limping along on the scale of the aforementioned short-range road-building program.
Archimedes knew that the world could be moved with a long enough lever. In fact some very powerful engineering principles had been understood for a long time, but their mass exploitation using the materials technology of the day was another matter. Nice idea, Archie, but who's going to make you this lever? Well, if you can only wait till 1870, Henry Bessemer's yer man.
Before we get dewy-eyed about this Titan among Titans, it's worth pointing out that his breakthrough, as well as most of the other breakthroughs of the 19th Century, happened in Sheffield too. Just you load of Southern Jessies4 remember this next time you sneer at our suitability to host the World Athletic Championships. Or snigger at our football teams. Steel is the fabric of modern civilisation, and an abundance of its technology originated in Sheffield. Had the discoveries made in Sheffield never taken place, it would write off a good couple of years of your life expectancy.5
Bessemer's convertor could turn tons of iron into steel in minutes. He called its product "malleable iron", but this time it really was volume steel. SteelTM. What a word. Speak it only with awe.
And the Modern World was suddenly possible, and innovation flourished as the markets boomed. Hadfield introduced manganese, and construction steels were born. Brearley alloyed with chrome and nickel, and created stainless. As the 20th Century dawned, a Machine Age was rising in fiery glory, and Mechanically-Advantaged Man seized His world.
The Twentieth Century
The Machine Age in Europe, however, was destined to flourish only for a single generation. The sons of its champions went to their slaughter in Flanders, and the myth of Steel as the ultimate Tool of War was exploded for ever. In another place, though, its reality as the feedstuff of mass consumerism had been properly recognised. The new century began with the rise of American Steel, in perfect harmony with American Capitalism.
The Industrial History of the World is for some reason littered with false attributions. Who invented the Science of Mass Production? Henry Ford is the stock answer, but he merely copied the principles of the first American Giant of Steel some twenty years before. Frederick Taylor and his doctrine of Scientific Management ushered in the enduring Machine Age, in a veritable second miracle at Bethlehem. And if that sounds sacreligious, there will be no apology. You owe more to these awe-inspiring Temples of Industry than you will ever know.
So far, most of the process development had targetted melting and refining, and the forming process was starting to lag behind. America's great engineering legacy was a redressing of this balance through the invention of the Hot Strip Mill. Perhaps the most exhilarating steelplant operation of them all, these magnificent machines break down a massive block of metal into a red-hot streaming ribbon, and capture it at the very point of its flight in a fabulous contraption which winds it into a coil. The Hot Strip Mill gave birth to the automobile age, the metals packaging industry, the modern home with its array of consumer white goods. It has made your life what it is today.
Now that volume steel was finally established, a scrap steel economy soon appeared in its wake. Electric arc steelmaking was developed, and the most significant recycling process that mankind has yet devised came into being. Here's another little known fact for you to take on board. The importance of the recycling of aluminium (or, if you prefer, aluminum) is a clever but ultimately cynical marketing con-trick. Sure, the aluminium industry relies on recycling for its competitiveness, but the activity is pretty well irrelevant in environmental terms. Ton for ton, the steel recycled in a single year outweighs all the aluminium ever produced in the entire history of the world.
Right up to the present day, the development of the steel industry has progressed, and the cradle of its technology has swung back to Europe, via a brief but instructive holiday in Japan. Its highlights include Basic Oxygen Steelmaking, with single converters blowing down three hundred tonnes of steel at a time in a mere twenty minutes. Also worthy of mention are continuous casting, thin slab casting, and in the last couple of years the first commercial implementations of endless rolling processes capable of converting molten cast metal directly into strip. Fifty years ago, the raw materials fed to the steelmaking process took about a week to reach strip form. The fastest plants today are pushing a single shift. Eight hours. A staggering advance.
There is another side to this coin. The workforce of today has been literally decimated compared with the one that Bessemer knew. Less than a hundred years after Taylor bestrode it like a Colossus, Bethlehem Steel has filed for bankruptcy. Steel is a commodity, and the economies that created it are now too rich to produce it. In an era of globalisation, steel's strategic significance is no longer fundamental to individual nations. Steel production is moving inexorably away from the shores of Western Europe, North America and Japan. It will be gone altogether within twenty years.
But it's pointless to despair about this. Progress and market economics take irresistible forms. Steel deserves no special privilege in our modern age. Nor did coal. Nor does agriculture. Nor, when their sunset is nigh, will the service industries that have largely supplanted the manufacturing traditions of the West.
But just look at the process. Regard the machines, these amazing machines wreathed in fire, defying the Works of Hell itself. This industry is nobler yet than men hewing coal, far nobler than men ploughing land, infinitely nobler than men tapping keyboards. It is nobler than the Space Shuttle and the sundering of the atom, because it is ultimately much more significant in all of our lives. And the machines and processes of this industry capture the imagination of the fortunate few that experience them, and they live in their memories for all time. Though shamefully unsung, these are truly the greatest technological achievements of Mankind.
There is a Ribbon of Fire running around the World.
It runs Day and Night.
It runs out of the Past and into the Future
And it Feeds the World.
Few among Millions know this.
We are the few who tend the Ribbon of Fire.
Long May it Serve us All6
There is a Ribbon of Fire running around the World.
It runs Day and Night.
It runs out of the Past and into the Future
And it Feeds the World.
Few among Millions know this.
We are the few who tend the Ribbon of Fire.
Long May it Serve us All6