Best talks about the influence factors of powder metallurgy on Damascus steel
time：2020-06-04Views：464 Author：Best Seiko
Damascus steel, modern refers to steel with a pattern on the surface. The traditional Damascus steel is mainly divided into two types according to the cause: the first is cast-type Damascus steel, also known as Uz steel, which was produced in ancient India and its texture was crystallized during the casting process, and the process has now been lost; second The type is forged Damascus steel, also known as welded texture steel. Its texture is formed by folding and forging two or more steel materials. This technique is very common and is used in all regions, but the style is different. But in modern times, the traditional Damascus steel is no longer a rival to stainless steel products in terms of performance or cost. However, just as the Damascus steel tended to decline, the contemporary Damascus steel using powder metallurgy new technology entered people's sight, making people see hope for the reapplication of this ancient steel...In modern terms, only one The steel with composition is called single steel, and the steel with more than two components is called composite steel. Damascus steel can be regarded as a composite steel with obvious texture. Damascus steel was a representative of high-end high-quality steel in ancient times, because for single steel, its hardness and toughness are always a pair of irreconcilable contradictions-the higher the carbon content of the steel, the higher the hardness, and the lower the toughness , Low toughness is easy to fold and collapse; the lower the carbon content, the higher the toughness, and the lower hardness makes the manufactured weapon easy to bend and curl. And Damascus steel is made of two kinds of steel, so it has a good balance between hardness and toughness. In addition, the special texture presented by Damascus steel is also its unique identity feature. Not only is it distinguished from other steels in appearance, its various textures also have a very high artistic effect, reflecting the uniqueness of different regions and even different producers. style. After the modern era, modern industrial steelmaking technology has developed rapidly. People can 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. It is difficult to do. These elements play an important role in the performance of steel. For example, chromium can increase the hardness and strength of steel and improve its oxidation resistance to form stainless steel. Sulfur and phosphorus are harmful elements. The less content in steel, the better. . Modern technology can make the content of chemical elements reach a very good state, so that the performance of modern single steel far exceeds the ancient level. This situation has caused the decline of Damascus steel. In the eyes of many people, Damascus steel has become a luxury product that can't be used, and can only be played as a purely ornamental craft. So, if two modern single steels are combined to make Damascus steel, is the performance even better? In theory, this is affirmative, but in actual operation, it faces difficulties that seem to be insurmountable. Since modern high-quality steel is alloy stainless steel, under high temperature conditions, the surface of the steel must oxidize, and the melting point of oxides of chromium, tungsten and other elements in modern high-quality steel is higher than that of steel. These oxides are sandwiched between The middle of the two pieces of steel prevents them from joining together. Even if it is barely forged, there will be a phenomenon of "ash", and the layers are not tightly combined. Therefore, alloying elements can greatly improve the performance of single steel, but at the same time create a serious obstacle to the folding and forging technology. The solution adopted by some people is forging in an oxygen-free environment. Although it can be successful, the cost of this method is too high, the process is too cumbersome, the operation is very difficult, and it is difficult to be widely used. However, as the saying goes, "Shan Zhongshui has no way to reconcile doubts, there will be another village in the willow." In the late 20th century, the powder metallurgy technology developed in Sweden brought a new turn for Damascus steel. From 1992 to 1995, the Swedish Erasteel company added a set of powder parting equipment in the production process of powder steel, so that the powders of the two steels were arranged in a layer-by-layer manner through this parting equipment, and then carried out In the next high-temperature and high-pressure welding process, powder metallurgy Damascus with parallel grains is formed. Modern steelmaking technology can achieve a very good ratio of chemical elements, but this technology is not perfect. The traditional steelmaking method is to use liquid argon blowing treatment, vacuum degassing, desulfurization outside the furnace, and directly add a certain metal in the steelmaking furnace to achieve the required ratio of various elements, and then enter the refractory In the ladle made of brick or refractory cement, the ladle is poured into the casting mold and cooled to obtain a steel ingot. In this process, the distribution of various chemical elements in the steel-making furnace is in a very uniform and ideal state. After entering the ladle, the temperature begins to decrease. At this time, the same kind of components in the molten steel will aggregate, waiting until it enters the casting mold. With complete cooling, the aggregation phenomenon is more serious, and the chemical composition is far less uniform than when it is in the furnace. There is a saying that "gold is in the furnace, silver is in the bag, and stone is the cooling", which is what it means. In theory, using powder metallurgy to manufacture Damascus steel, you can choose any two kinds of steel in the world to fuse, but the actual operation must be certain. The selection of the original steel generally needs to consider the following factors: 1. Complementary performance-the combination of ingredients should meet the specific application; 2. Heat treatment parameters-the two steels should have the same or similar heat treatment process parameters; 3. Thermal engineering Effect—The two steels should have the same or similar thermal effects to ensure that the steel performance is not affected during forging or heat treatment; 4. Corrosion grains—the content of at least one element in the two steels is sufficiently different to ensure the grain clarity degree. Damascus cutter steel is mainly used to make various forms of cutters, and is not limited by its shape. Some people use it to make hunting knives for peeling and cutting meat. They are also very useful. They can also be made into small folding knives that you can carry with you. You can easily use it to cut ropes and open cartons. Although these things can be done with ordinary knives, the feeling of using Damascus is different. Others use it to make traditional long swords. The cost of steel alone is several thousand yuan, which is extremely luxurious. Nowadays, jewelry made of powder metallurgy Damascus jewelry steel is very popular. In terms of style, the name "Damascus steel" shows a spirit of martial arts, so it is more suitable for men to wear. If a man always wears gold and silver, it may make people feel less masculine, and wearing Damascus steel jewelry will not have this "side effect". From the perspective of raw material prices, the prices of powder metallurgy Damascus jewelry steel and silver are similar, but the silver products are still usable in the collection of scrap, and the scrap of Damascus steel is completely scrap iron, so the price of its finished products is higher than that of silver. Powder metallurgy Damascus jewelry steel can also be used to make a variety of products, such as tableware, accessories for automobiles and furniture. It is said that domestic mobile phone manufacturers are already preparing to develop mobile phone cases made of Damascus steel.