Damascus and Bulat - what is the difference?

Damascus and Bulat - what is the difference?

Zlatoust is one of the oldest cities in the Southern Urals, founded in 1754 as an ironworks. The whole history of Chrysostom is inextricably linked with metal and its processing. Chrysostom is the birthplace of Russian bulat. At the Zlatoust plant, the famous Russian metallurgist Pavel Anosov in 1833 revealed the secret of bullat steel and since 1837, the Zlatoust arms factory produced bullat blades.

Damascus and Bulat – what is the difference? In principle, today any patterned steel can be called both mulatto and Damascus – and this would not be a gross mistake. However, historians of metallurgy distinguish by the production technology of pure "Bulat" - cast patterned steel and "Damascus" - "welded bulat", what the Company "AIR" is doing today in Zlatoust. If you stick to this terminology, then there will be no confusion in terms.

The word "Bulat" is of Persian origin, from the word "pulad", which means "steel". This is carbon cast steel, which due to a special method of production is distinguished by a peculiar structure and “pattern” of the surface, has high hardness and elasticity. (BSE). 1969-1978.

It was called Damascus steel from the city of Damascus, where it could be bought. Damascus was once the largest trade and craft center.

In fact, the birthplace of bulat is India, and bulat is often called wuts – in the Indian dialect “wuts” means – an ingot of steel fused in the form of a flat flat cake.

The ingots actually had the appearance of a small flat bread cake with a diameter of about 12.5 cm, 2.5 cm thick and weighing 900 grams. Ingots of bulat were brought from India to the city of Damascus, from where merchant caravans “bread” Wutz were exported to Persia, Egypt and further to the Middle East. Each "bread" was cut in half into equal parts so that the buyer could consider the structure of the metal.

For almost 3 thousand years, the method of smelting bulat remained secret, and the best blades of antiquity were forged only by masters of India. They were distinguished by many amazing properties: these blades had a characteristic pattern - a patterned structure, the blades had unusual hardness, strength, elasticity, good cutting properties. The best blades easily cut the gas handkerchief on the fly in the air, easily cut the blade from softer grades of steel. They could even girdle around the belt like a belt, and after that it did not bend, did not change its shape, but returned to its original position. At that time, there were no cold weapons that could compete with the bullat.

But in the Middle Ages, the secret of making bullate steel was lost. Despite the loss of the secret, interest in the bulat did not disappear, many scientists from different countries tried to reveal the secret, among them was the famous English physicist Faraday. What recipes were not offered, what was not added to iron: precious stones, gold, silver, platinum... Everything went well, but to no avail. This secret, surrounded by an impenetrable cover, is revealed by P. P. Anosov, 10 years of special hard work at the Zlatoust plant were crowned with success - the secrets of the bulat no longer existed, in 1833 Anosov received a Russian bulat. “The stripe bent without the slightest damage, emitted a clean and high ringing. The polished end crushed the best English chisels, Anosov wrote in the Mining Journal.

So what is the bulat, over the mystery of which so long and stubbornly fought? “Iron and carbon and nothing more,” writes Anosov, “It’s all about the purity of the starting materials and the method of cooling and crystallization” (N. A. Mezenin). Interesting about iron. M.: Metallurgy, 1985.

The loss of the secretion of bulat was associated with a decrease in demand for it, which was caused by the start of industrial production of quality steels. And today our metallurgists claim that they have only historical interest in bulat, because in comparison with modern steel and alloy grades, bulat is inferior to them in many characteristics, and the process of making bulat is very time-consuming and lengthy and requires high art. Cast bulat is obtained by melting the initial components (classically – iron and carbon) in a crucible furnace. The smelting lasts up to 6 hours: about 4 hours the desired temperature is injected, and about 2 hours the metal is melted. The metal then cools in the oven. As a result of slow cooling of the ingot, a heterogeneous structure of iron and cementite is formed in it - a carbide mesh along the boundaries of metal grains, giving a pattern on the blade. You can melt the bulat for a long time, and then it turns out that the ingot turned out with a crack and all efforts are in vain.

Damascus steel – as they now say – “welded bulat” was most likely obtained by accident. There are suggestions that due to the shortage of metal, blacksmiths often used old iron clips, welded them together and forged them, a “bulat” pattern was obtained on the blades.

Welded bulat, as the name suggests, is obtained by the method of forging welding. If the compound of components (Fe and C) is achieved when melting in a kiln, then the same connection in damask is achieved by forging, which is no less difficult. To obtain a welded bulate, a packet of steels with different carbon content is assembled, which is welded together, forged, then folded in another way (for example, in half) and forged again - as housewives make layered dough. That's the right number of times.

At the same time, the number of layers increases exponentially. So, if the initial packet had 8 layers, then after the first forging they become 16, after the second 32, after the seventh 1024, etc. Welded bulat - damask is inferior in hardness to pure "Bulat". At the same time, the quality of damask blades is higher than that of ordinary steel.

Special methods of forging blacksmiths "AiR" achieve various drawings: - "Wild" pattern of damask is obtained by random forging of metal layers.

- "Stamp" damask with a regular, repetitive pattern is formed as a result of applying a special stamp - a stamp of a strictly ordered relief, the layers of which are distorted during forging in a given order.

- Especially beautiful is the pattern of the "Turkish" damask, so in the XVII-XVIII centuries it was called in Europe. It turns out as a result of repeated twisting of the workpiece around its axis during forging.

- "Kruchenko" - is actually a type of Turkish damask, it is obtained by twisting thin tightly twisted rods, which for welding are folded into a narrow high stack.

- From the same series and the drawing "Twist" - from English. Twisting, twisting, twisting.

Under the brand ZD produces Damask enterprise "AIR" Zlatoust.

Technology "AIR" allows welding and stainless steel (the ability of steel to weld decreases with increasing content of carbon and other alloying elements.

The basis of the company’s technology is diffusion welding of steels and alloys of various compositions. At the same time, great demands are made on the quality of the surface. Preliminary surface treatment is carried out by high-precision modern flat grinding machines. Some materials are subjected to sandblasting. Before compacting, the workpieces are degreased in ultrasonic baths, surface preparation is carried out by electrochemical activation methods. The high quality of diffusion welding processes of high-alloy steels is ensured by the creation of an active controlled atmosphere. For one technological cycle, depending on the composition of the composition, a block with 30-300 layers is obtained. If necessary, the resulting block is forged, grinded and subjected to further diffusion welding.

- Zladinox (ZLAtoust+Damast+INOXidable) - under this name the Company creates weatherproof damask.

Decoding of the Damask brand: ZD-0803 is a low-alloyed carbon damask, ZDI-1016 is a carbon high-alloy weatherproof damask. The first two digits in the designation correspond to the average carbon content, the second two digits correspond to the average content of alloying elements (chromium, molybdenum, vanadium, etc.). For example, ZDI-1016 is a high-alloy weatherproof damask with an average carbon content of 1.0% and an average alloying element content of 16.0%.

AIR’s forgemen do not stop experimenting with the legendary metal and create decorative mosaic damask and even Art-Damascus.

Samples of these beautiful and complex in the production of metals can be seen on a tour of the enterprise.

In the manufacture of such a damask, the master welds not flat steel plates, but a bunch of thin rods or wires. The rods can have a very complex cross-section. It is required to weld the rods not as casually, but in a strictly defined order, so that after forging a steel mosaic appears.

Art-Damascus is not a drawing on a blade, but two metals in one blade. With the help of an electroerosion apparatus in the thickness of the steel block, the conceived image is cut out and filled with an insert of an identical shape, but of a different metal. After that, both fragments are welded into a single whole, and the forging process begins, as a result of which Art-Damascus is created. It amazes how realistically blacksmiths manage to convey even power and become running horses. True art has no boundaries. Thus, the arsenal of domestic high-quality steels was replenished with Zlatoust Art-Damascus.

Production of Zlatoust Damask (launched in 2010) is one of the activities of AIR.

In addition, the company is successfully working in other areas:

– production of handmade author’s products decorated in the traditions of Zlatoust engraving on metal;

Production of knives for tourism, hunting and fishing.