Anne Marie Helmenstine, Ph.D.
Damascus steel is a famed type of steel recognizable by the watery or wavy light and dark pattern of the metal. Aside from being beautiful, Damascus steel was valued because it maintained a keen edge, yet was hard and flexible. Weapons made from Damascus steel were vastly superior to weapons formed from iron! Although modern high-carbon steels made using the 19th century Bessemer process surpass the quality of Damascus steel, it remains an outstanding material, particularly for its day.
There are two types of Damascus steel: cast Damascus steel and pattern-welded Damascus steel.
Where Damascus Steel Gets Its Name
It's unclear exactly why Damascus steel is called Damascus steel. Three popular plausible origins are:
- It refers to steel made in Damascus.
- It refers to steel purchased or traded from Damascus.
- It refers to the similarity the pattern in the steel has to damask fabric.
Although the steel may have been made in Damascus at some point and the pattern does somewhat resemble damask, it's certainly true Damascus steel became a popular trade item for the city.
Cast Damascus Steel
No one has replicated the original method of making Damascus steel because it was cast from wootz, a type of steel originally made in India over two thousand years ago. India began producing wootz well before the birth of Christ, but the weapons and other items made from wootz became truly popular in the 3rd and 4th century as trade items sold in the city of Damascus, in what is modern Syria. The techniques for making wootz were lost in the 1700s, so the source material for Damascus steel was lost. Although a great deal of research and reverse engineering has tried to replicate cast Damascus steel, no one has successfully cast a similar material.
Cast wootz steel was made by melting together iron and steel together with charcoal under a reducing (little to no oxygen) atmosphere. Under these conditions, the metal absorbed carbon from charcoal. Slow cooling of the alloy resulted in a crystalline material containing carbide. Damascus steel was made by forging wootz into swords and other objects. It required considerable skill to maintain constant temperatures to produce steel with the characteristic wavy pattern.
Pattern-Welded Damascus Steel
If you buy modern "Damascus" steel you could be getting a metal that has merely been etched (surface treated) to produce a light/dark pattern. This is not really Damascus steel since the pattern can be worn away.Knives and other modern objects made from pattern-welded Damascus steel bear the watery pattern all the way through the metal and possess many of the same characteristics of the original Damascus metal. Pattern-welded steel is made by layering iron and steel and forging the metals together by hammering them at high temperature to form a welded bond. A flux seals the joint to keep out oxygen. Forge welding multiple layers produces the watery effect characteristic of this type of Damascus steel, although other patterns are possible.
References
Figiel, Leo S. (1991). On Damascus Steel. Atlantis Arts Press. pp. 10–11. ISBN 978-0-9628711-0-8.
John D. Verhoeven (2002). Materials Technology. Steel Research 73 no. 8.
C. S. Smith, A History of Metallography, University Press, Chicago (1960).
Goddard, Wayne (2000). The Wonder of Knifemaking. Krause. pp. 107–120. ISBN 978-0-87341-798-3.
Damaskus stål
Damaskus er et stål som du kan se ejendommelige mønstre dannet af skiftevis forskellige typer af metal.Til fremstilling af denne type stål bruge emner med forskellige mængder af kulstof i sammensætningen. De er først forbundet med svejsning, og senere gentagelig smedning. Som resultatet af forskellige metal type bevægelse du kan se simpelt mønster af bølgeformede linjer.
Hvis du fortsætte med smedning, ved hjælp af særlige teknikker kan du opnå en fantastisk klarhed og skønhed af mønster
Men vigtigst den er høj kvalitet af færdig stål. De fleste knivførere mener at der skal bruges 300-500 lag for at skabe en kvalitetskniv.
Denne besværlige proces giver et unikt stål. Damaskusstål kombinerer stor hårdhed og evne til at holde en skarp æg med stor sejhed og elasticitet. Lag med meget kulstof giver klingen skarphed og styrke og lag med lav - fleksibilitet og modstandsdygtighed over for bøjning.
Der er to typer af Damaskus stål: smedet Damaskus og mønster-svejset Damaskus stål.
Mønster-svejset Damaskus Stål
Hvis du køber moderne "Damaskus" stål risikere du at få et metal, der blot er blevet ætset (overfladebehandlet) til at producere en lys / mørk mønster. Dette er ikke rigtig Damaskus stål, da mønsteret kan bæres væk.Knive og andre moderne genstande lavet af mønstersvejset Damaskus stål bærer det vandige mønster hele vejen gennem metallet og har mange af de samme egenskaber ved det oprindelige Damaskus.
Mønstersvejset Damaskus er lavet ved lagdeling jern og stål og smedning metallerne sammen ved hamring dem ved høj temperatur til at danne en svejset binding. En flux forsegler leddet for at holde ilt ude. Smede svejsning i flere lag producerer den vandige effekt typisk for denne type Damaskus stål.
Også andre mønstre er mulige.