What method is used to fold steel



 

The term Damascus steel or damask (from Arabic دمشق dimašq, Name of the city of Damascus, the capital of Syria) describes a material made of one or more types of iron / steel, which in the polished or etched state reveals a clear structure made up of several alternating areas of hard and soft material. Damascus steel combines the good properties of soft and hard iron or steel, i.e. it is both flexible and sharp. Strictly speaking, Damascus steel only refers to the steel produced in the oriental-Arabic region using the crucible melting process. However, the term is also frequently used for composite steel, as it was and is mainly produced in Europe. A distinction is therefore not possible. The importance of damascus steel in antiquity consisted primarily in the use of the material for weapon manufacture, mainly for edged weapons. One could even say that this material was only "invented" for the manufacture of edged weapons.

The source material

iron and Steel

The starting material for the production of Damascus steel is iron or steel. Iron is the chemical element and is the main component of steel. Steel refers to an alloy of iron with carbon, whereby the carbon content of the iron must not have more than 2.06% by weight. Due to its low carbon content and its purity, steel can be easily deformed or forged.

A distinction between iron and steel has only been made since modern times. In earlier times it was only important to produce malleable material. For this reason and for the sake of simplification, both terms will be used equally in the course of this text; there is no distinction!

Manufacture of the raw material

In ancient times, malleable material was produced in clay ovens (racing ovens). The iron ore piled up in the furnace (lawn iron stone) was brought to very high temperatures (around 1300 ° C) with the help of charcoal, whereby the rock melted and ran off as slag. The (remaining) shell produced in this way was inhomogeneous, but could be further processed directly by forging. It was not until the Middle Ages that there were blast furnaces that could produce liquid pig iron.

Bronze and iron

Plain iron is very soft and hardly better suited for weapon production than bronze, which was used before the Iron Age. It also rusts quickly. Nevertheless, iron replaced bronze relatively quickly, as it was much easier to obtain and therefore “cheaper”. The procurement of raw materials for the production of bronze also became increasingly difficult.

Hardenability

One of the most important properties of iron, which also determines its later superiority over bronze, is its hardenability. The hardening of iron was probably discovered quite early on by simply extinguishing the glowing iron in water. The iron that was quenched in this way was harder than an iron that was simply left to cool in the air. How long it took until this hardening process was consciously and specifically applied is unclear.

There are many modern methods of hardening iron, but the hardening process in ancient times was limited to quenching the glowing iron in cold water. During hardening, microcrystalline structures of the carbon compounds form in the metal lattice, which have a high level of strength and hardness. Only iron with a carbon content of more than 0.2% can be hardened. As the carbon content increases, the degree of hardness increases, but the iron also becomes more brittle.

It is not only the carbon content in iron that determines its properties; other trace elements such as phosphorus (for hardness), manganese (makes iron tough, tensile strength) or silicon (makes iron flexible) also play a role here.

Regardless of this, the master blacksmiths practiced in ancient times. They could only rely on their experience; the chemical relationships were only discovered in our time. The blacksmiths of that time could only influence the carbon content, remove slag from the metal and bring about a homogenization of the iron. The other chemical compositions of the raw material determined the nature or the place of origin of the iron ore.

The problem with the sword

The problem with the production of edged weapons, for example that of a sword, arises from the properties of the hardened iron. Because of its intended use, a sword had to withstand high loads, be light and remain sharp, not break or bend - the life of the wearer could depend on it.

With very hard steel you get a blade that stays sharp for a long time and does not bend, but it breaks very easily. With very soft steel you get a blade that doesn't break, but doesn't stay sharp and bends easily.

A soft steel sword was still preferable to a hard steel sword. A bent sword can be straightened again, a blunt one can be sharpened, but a broken one - no matter how sharp it is - can only be thrown away.

It was probably very early on to look for ways to produce a material that had the good properties of soft and hard steel, i.e. strong and sharp, but also flexible and unbreakable.

The "real" damask

origin

The name Damask is derived from the city of Damascus, the capital of Syria. The steel, presumably manufactured in India, and later also in the whole of the Oriental-Arab region, is mistakenly associated with Damascus. It is likely that weapons made from this material were simply increasingly traded in Damascus, since the city had been a major trading metropolis since the Middle Ages. It can be assumed that the term damask, for the steel of these oriental weapons, has been established since the Middle Ages.

quality

The oriental damask is often referred to as legendary and far superior to medieval European swords. But this comes from the realm of legends. There were also great differences in quality with the oriental steels. Nevertheless, there are swords of excellent quality, which have an excellent edge retention and break resistance and have a high artistic value.

Manufacturing

Solid evidence of the manufacture of this steel has only existed since the late Middle Ages. Reports of previous damask blades have no scientific basis.[1] In the case of this steel, it is the wave-like arrangement of martensite particles in the structure that determine the excellent properties, which is already achieved when the iron is refined and not by forging several types of steel. So one cannot speak of damask forging technology here. This crude steel, produced using the crucible melting process, is known as Wootz.

With these swords, too, a beautiful wave-shaped pattern is created on the blade by polishing or etching. Such swords were still used around the end of the 18th century. manufactured, the production of this steel has since been forgotten. There are several assumptions about the production process; these relate to certain additives of vegetable material or to certain ingredients of the raw material.

research

In 2006, electron microscopic examinations at the Technical University of Dresden found nanotubes up to 50 nm in length and 10 to 20 nm in diameter made of carbon atoms in a Damascus sword from the 17th century, which indicate a still unknown metallurgical process. There is speculation that, for example, wood or leaves were added to the melt using special Indian iron ores as catalysts. [2]

Wootz

The starting material, the so-called Wootz bar, consists of very pure iron, approx. 1.5% carbon and tiny traces of impurities from vanadium, molybdenum, chromium, niobium or manganese. The material is melted and then slowly cooled. Austenite crystals slowly form. They have an elongated, fir tree-like shape and push themselves further and further into the melt. The impurities do not fit into the crystal lattice and are pushed into the gaps.

If the material continues to cool and falls below the austenite lower limit temperature, cementite particles form, which are randomly distributed. If the steel is now forged, the cementite particles volatilize again, except in the boundary area between the austenite crystals, where the foreign matter has accumulated. The steel is now each time heated up to the temperature range in which new cementite particles are formed. Then the steel is forged. This is how the cementite lines are gradually created. In order to make them visible, the surface still has to be etched.

Due to the increasing purity and reproducibility of mono steels, damask has recently been reduced to its decorative effect. However, some connoisseurs and specialists are still of the opinion that the fire-forged composite steel blade is the more noble and ultimately also the better crafted variant. In addition, these handcrafted masterpieces are absolutely unique and show a "living" steel.

The European damask

Differences to oriental damask

European damask is fundamentally different from the oriental one. In this case, it is not the raw material after the iron has been smelted that determines the quality and properties, but the forging connection of soft and hard types of iron in the fire welding process.

History and Development

There are various theories about the development of damascus steel in Europe. One of them is that European damask was an attempt to copy oriental art. However, this is very unlikely, since the first blades with this kind of damascus have been found in Europe since the Latène period. Another theory is that steel was simply invented at some point by one or more blacksmiths. This is rather obvious. It is also possible that over time it was recognized that swords that were forged from old things (after all, iron was an expensive raw material) were much more durable. The blades were stronger, more flexible and more sharp than those made from a “fresh” piece of iron. The different types of scrap iron with their different carbon content were responsible for this.

Such “random damask” can also be found, for example, in antique and medieval tools, which can sometimes lead to astonishment. Here, too, new things were simply forged using scrap iron and not necessarily the "swords into plowshares".

  Damask structures can be recognized in some cases from finds in the ground, as the softer layers of the steel weather faster than the hard ones, which reveals the structure of the steel.

Swords made of so-called wild damask can already be found in the Hallstatt period.[3] No uniform structure can be seen in these. For this reason, it is believed that this damask was made rather unconsciously (from old things). There are, however, somewhat later pieces of evidence that have a uniform structure, and were even forged from several strands. So one can at least speak of a conscious development here. This development reached its climax in the Latène period with the world-famous bulbous pommel swords of the Celts - which were undoubtedly deliberately made from Damascus steel and represent an outstanding craftsmanship. [4]

Nevertheless, the swords of the Celts are generally considered to be of poor quality, which is supported by Roman reports: "The Celtic warriors often had to withdraw from the turmoil behind their ranks to straighten their swords with their feet." Lore.However, this is not a paradox but completely understandable, it is not possible to have a whole army - possibly. Equip weapons of the highest quality even in the shortest possible time. High-quality swords were probably reserved for the slightly higher-ranking men with a better budget.

It is not known whether the beginnings can be found in the culture of the Celts. It is possible that the technology was adopted by other peoples, such as the Scythians, but it was the Celts who brought it to perfection.

In the Roman Empire, in addition to folded mono steel (made from a single type of steel), Damascus steel was also used, but finds from this period are rare. Even after the times of the Celts and Romans, Damascus steel was used and enhanced for the manufacture of edged weapons.

The Germanic tribes (the Merovingians are often called in this context) created excellent weapons with extremely artistic damask work at the time of the Great Migration, which were also elaborately differentially hardened.[5]

For the first time, not only functionality was in the foreground, but also artistic implementation - whereby an artistic blade also promised a high level of functionality, of course. Many swords even bore names and were absolutely cultural objects. At that time the damask structures were probably brought to light with a similar polishing process as is still used today on Japanese samurai swords. With the help of whetstones, such a flat surface is created on the blade that one can, so to speak, look into the “soul of the steel”, i.e. see the individual layers of the damask due to their different colors. But it is also conceivable that an etching process was used with which a similar effect can be achieved.

It is surprising and worth mentioning here that there are finds of Germanic Sachs blades and late Roman swords, which have a structure and hardening that is equivalent to a Japanese samurai sword. This was found out by having selected blades polished in Japan using the traditional polishing process.[6][7]Research continues.

 

The development of damask steel went so far that in the late Middle Ages damask was used almost exclusively for the manufacture of edged weapons. Among others, Solingen has been a stronghold of blade production since the Middle Ages. At the time of the 30 Years War, swords made of Damascus steel were mass-produced. The famous, extremely fine Turkish damask also comes from Solingen. Damascus steel only lost its importance with the availability of good, cheap steel at the time of the industrial revolution.

 

Damask in Southeast Asia

Mainly in Indonesia and Malaysia, damask was also made by combining hard and soft iron. This was mainly used for the production of the so-called kris (a dagger with a pointed, mostly wavy blade). A special feature here is that, among other things, iron meteorites were used to manufacture this steel. This was found out in chemical analyzes of the blade material, as iron meteorites contain the rare element nickel.

Damask and the samurai sword

Samurai swords are not actually made of damascus steel. Often used, different blade structures with z. B. inlaid, softer steel and the differential hardening of the blade have nothing to do with Damascus steel. The steel for making a Japanese sword is also folded, but the reason for this is to achieve a certain homogeneity (even distribution of the chemical components in the steel) and the removal of slag, which is essential due to the highly impure raw material (tamahagane). The number of folds hardly plays a role here, it is left to the experience of the blacksmith to determine when the material is "pure" enough.

If one were to call this process damask forging, the material of almost every antique, forged object would have to be called damask. The inhomogeneous material (shell) produced from a racing furnace could only be further processed into a usable material by folding.

The making of Japanese swords has its own theme and is described in more detail elsewhere.

Use in firearms

The barrels of firearms have always been made from damask (fire-welded composite). The material offers exactly the properties that are required for firearms; it is flexible, tough and strong. Early cast barrels (found in hand rifles, hook rifles and wall rifles, among others) were heavier and could burst due to the pressure when firing, which was associated with a high risk for the shooter. With damask barrels, despite the lower weight, bursting was almost impossible.

The manufacture of the damask barrel was done, for example, by winding individual iron wires over a rod and then forging them together. A very nice example can be seen in the arms museum in Suhl, in which a band of several twisted damask steel strands is forged around a rod to form a barrel.

Damascus steel today

 

use

Nowadays, damascus steel is enjoying increasing popularity again, especially for the manufacture of kitchen and hunting knives. But everyday objects and jewelry are also made from it, the latter due to the aesthetic appeal of the etched surface.

importance

The importance of this steel is no longer very high, as there are now mono steels (made from a single type of steel) that are in no way inferior to damask steel. In addition, the risk of breakage with a short knife is not as high as with a long sword, good edge retention, which can also be achieved with a monosteel, is much more important here. There are also very large qualitative differences between the damascus steels of the individual manufacturers / craftsmen. Damask, regardless of its quality, sells well.

In addition, there is the problem with knives that the cutting edge can wear out "saw-like", i.e. This means that the soft layers in the composite wear out much faster than the hard ones. Since both layers also form the cutting edge, this problem must be taken into account. This problem have z. B. monosteel blades or three-layer steel blades are not.

Manufacturing

Hand-forged Damascus steel is still produced today in a very similar way to how it was in the past.

At the beginning, several layers, usually 3 to 8, are laid one on top of the other and welded in the forge. The composite is then separated lengthways or crossways, placed on top of one another and forged again (folds). The entire procedure is repeated several times.

Since the number of layers doubles each time it is laid on top of one another, you get hundreds of layers after just a few repetitions. The main difficulty with fire welding is that the material must not exceed a certain temperature, otherwise the carbon will burn, and at the same time the material must not scale (oxidize) too much, because it can then no longer be forged together. Since the steel starts to burn before the melting point (oxidation), quartz sand or borax is scattered over the area to be welded towards the end of the heating process. This melts into a liquid glass layer and thus protects the steel from the oxygen. The right time for this is when the first stars (sparks) of burning carbon appear. A glassy shield is created that encloses the two parts to be welded. This serves not only as protection, but also as a time bridge, which allows the blacksmith to carry the welded parts to the anvil and join them there with one precise blow.

To get beautiful patterns on the surface, the steel can also be twisted (Torsion damask) or "asymmetrically" processed further (wild damask). After hardening, the Damascus steel is etched in order to make the pattern visible, since the various layers in acid turn light (nickel) or dark (manganese) depending on the carbon content or alloy. The cutting edges are then usually post-hardened at the end. Today, chain damask, which is forged from motorcycle chains or chainsaw chains, is often used for knife production, which results in a very beautiful pattern.

Damasteel

Due to newer steelmaking processes, so-called Damasteel getting produced. This is a completely different material than classic Damascus steel. Damasteel consists of rust-resistant steel, which is refined by mixing the base material with steel chips during the manufacturing process. The process was only developed in 1993. The reason for the development was that the high-alloy steels cannot be hot-welded. Stainless steel is a high-alloy steel as it must contain more than 10% chromium in order not to rust.

Damascene

Damascus refers to an etching process on a polished metal surface, which is intended to simulate the pattern of damascus steel. It is not Damascus steel. Such counterfeits are often indistinguishable from real Damascus steel. In heraldry, damascene is understood to be the decoration of coats of arms with plant-like flourishes and tendril patterns in the style of arabesques [8].

See also

literature

  • Manfred Sachse; Damascus steel. Myth. History. Technology. application Stahleisen-Verlag 1993, ISBN 978-3514005204

swell

  1. Archeology Online - scotts_talisman_damastsalat_und_nanodraht
  2. M. Reibold, P. Paufler, A. A. Levin, W. Kochmann, N. Pätzke and D. C. Meyer: Materials: Carbon nanotubes in an ancient Damascus saber. Nature 444: 286 (2006). (English)
  3. Archeology Online - Esse Hammer Anvil
  4. The Celtic rapiers
  5. Materials and Process Engineering Department
  6. Secrets of European swordsmithing revealed
  7. Archeology online - Open a window
  8. http://home.datacomm.ch/hofer.harri/html/body_damaszierung.html

Categories: Tool Material | Steel | Forge