Effect of powder metallurgy on damask steel is analyzed

Damask steel, modern refers to the surface of the pattern of steel. The traditional damask steel is mainly divided into two types by cause of formation：

The first is the cast shape of Damascus steel, also known as uzh steel, made in ancient India, and the patterns are crystallized during the casting process；

The second is the forged damask steel, also known as welded grain steel, which is formed by folding and forging two or more kinds of steel. This technique is common, used in all parts of the world, but in different styles.

But in modern times, traditional Damascus steel is no longer a rival to stainless steel in both performance and cost.

However, as damask steel tends to decline, modern damask steel adopting new powder metallurgy technology has come into people's eyes, giving people hope for the re-application of this ancient steel...

In modern terms, steel with only one component is called monomer steel, and steel with more than two components is called composite steel. Damascus steel can be regarded as composite steel with obvious grain.

Damascus steel was the representative of high-grade steel in ancient times, because for single steel, its hardness and toughness are always an irreconcilable contradiction -- the higher the carbon content of steel, the higher the hardness is, while the lower the toughness, the lower the toughness is easy to break and collapse. The lower the carbon content, the higher the toughness, and the lower the hardness make the weapon easy to bend and roll. As damask steel is composed of two kinds of steel, it has achieved a good balance of hardness and toughness. In addition, the special patterns presented by Damascus steel are also its unique identity, which is not only distinguished from other types of steel in appearance, but also has a high artistic effect, reflecting the unique style of different regions and even different producers.

In modern times, with the rapid development of modern industrial steelmaking technology, people could not only control the content of carbon in steel, but also control the content of chromium, molybdenum, vanadium, manganese, tungsten, sulfur, phosphorus and other elements at will, which was difficult to do in ancient times. These elements play an important role in the performance of steel. For example, chromium can improve the hardness, strength and anti-oxidation of steel to form stainless steel, while sulfur and phosphorus are harmful elements. The less they are in steel, the better.

Modern technology can optimize the content of chemical elements, so that the performance of modern monomer steel far exceeds the level of ancient times. This situation has led to the decline of Damascus steel. In many people's eyes, Damascus steel has become a kind of "useless" luxury, which can only be used as a pure ornamental handicraft.

So, if use two kinds of modern monomer steel to combine make Damascus steel, is performance more excellent? In theory it is, but in practice it faces difficulties that seem insurmountable.

Thanks to modern high quality steel products are alloy, stainless steel under the condition of high temperature, the steel surface oxidation, inevitable and elements such as chromium in modern high quality steel and tungsten oxide melting point higher than the melting point of steel, the oxide sandwiched between to forging of two pieces of steel and prevent them from one, even if reluctantly forging close, also can have the phenomenon of "grey", is not closely between the layers.

Therefore, the alloy element can greatly improve the performance of monomer steel, but at the same time it creates serious obstacles for folding and forging technology. The solution adopted by some people is to forge in an anaerobic environment. Although it can be successful, this method is too expensive, the process is too complicated, and the operation is very difficult and difficult to be widely used.

However, the so-called "mountains and rivers are suspicious of no road, willow bright and another village". In the late 20th century, the development of powder metallurgy steelmaking technology in Sweden brought a new turn for Damascus steel.

From 1992 to 1995, Swedish Erasteel company added a set of equipment of powder mold parting in the production process of powder steel, so that the two kinds of steel powder were arranged in layers through this parting equipment, and the next step of high-temperature and high-pressure welding process was followed, forming parallel grain powder metallurgy Damascus steel.

Modern steelmaking technology can make the chemical elements to the best ratio, but this technology is not perfect. The traditional steelmaking method is to mix the liquid steel water into the ladle made of firebrick or refractory cement by blowing argon treatment, vacuum degasification, desulphurization outside the furnace and directly adding some metal to reach the required proportion of various elements. In this process, the distributions of various chemical elements in steel furnace is the most ideal state, evenly into the ladle, temperature began to reduce, then the same ingredient in steel, gathered phenomenon will occur until completely cooling into the mold, gathered phenomenon is more serious, the strict composition is far less than uniform in furnace. There is a saying, "in the furnace is gold, in the bag is silver, in the cooling is stone", which means this.

1、Performance complementarity - composition collocation should be satisfied for specific applications；

2、Heat treatment parameters - two types of steel shall have the same or similar heat treatment process parameters；

3、Thermal effect - both types of steel should have the same or similar thermal effect to ensure that steel properties are not affected during forging or heat treatment；

4、Etch lines - the contents of at least one element in two types of steel are sufficiently different to ensure the clarity of the lines.

Damask steel is mainly used to make all kinds of knives, regardless of its shape. Some people use it as a hunting knife to peel and cut meat. Can also be made into a compact folding knife, carry, meet cut rope, open carton and other things, can be easily handled with it. Although these things can be done with ordinary knives, the feeling of using Damascus is different. Some people use it to make traditional long swords. The cost of steel alone is several thousand yuan.

Now jewelry made from powder metallurgy steel of Damascus jewelry is very popular. Stylistically, the name "Damascus steel" suggests a martial spirit, and is therefore more suitable for men. If a man wears gold and silver all the time, it may feel less masculine, and wearing jewelry made of Damascus steel has no such "side effect". In terms of raw material price, the price of powder metallurgy Damascus jewelry steel is similar to that of silver, but the leftover material of silver production products can still be collected and used, while the leftover material of Damascus steel is completely scrap iron, so its finished product price is higher than that of silver. The powder metallurgy Damascus jewelry steel can also be used to make a variety of products, such as tableware, cars, furniture accessories, there are said to be mobile phone manufacturers in the country ready to develop Damascus steel mobile phone shell.