Diamond steel ХВ5: description, technical characteristics and application

Diamond is called alloy steel with an increased content of carbon, characterized by a special hardness. Comparing it with a precious stone is just a beautiful expression. On the level of hardness, this steel is much inferior to the diamond. It has not only a figurative poetic name, but also a technical one. The most common brand is denoted by the abbreviation XB5, which stands for chrome-tungsten. According to some parameters, diamond steel is superior to any other grades. It is widely used in the industry for cutting softer metals. Because of the sphere of the most frequent use, this steel is called instrumental. It was invented many centuries ago, but the modern process of obtaining it differs from the old one.

General characteristics

The properties of diamond steel are due to its chemical composition. The combination of iron and carbon creates exceptional hardness. In popular modern brands, chromium and tungsten are also added to give additional resistance to corrosion and high temperatures. The optimal content is 1% carbon in the alloy. The increase in its share in the composition of steel adversely affects the quality of products, as the viscosity and ductility of the material decrease with increasing hardness. Metal with a relatively high content of carbon becomes brittle. Blades and tools of diamond steel have excellent cutting properties, but can easily break. The hardness of XV5 alloy blades is 60-65 HRC on the Rockwell scale, which is the maximum. The limiting value of this parameter for any blade on this measuring system does not exceed 65 units.

Additional Items

A modern alloy contains about 1% chromium, which makes it unaffected by rust. But the amount of this component is limited, as it reduces the strength of the material. For comparison: the alloy is considered completely stainless with a content of at least 18% chromium. The composition of diamond steel XB5 also includes tungsten. It is an exceptionally refractory and dense metal with unique properties. In addition to heat resistance, tungsten is resistant to acids and other corrosive substances. It improves the cutting properties of steel and protects it from wear. The alloy ХВ5 contains 4-5% tungsten.

Tamahagane

The history of the invention of diamond steel goes back to medieval Japan. In the Samurai era, this metal was known as tamahagane. In Japanese, this means "precious steel". It was from it that the legendary samurai swords forged . There are many myths about the ancient Japanese cold weapons that testified to their belonging to the military class. One of the legends tells us that to test the quality of his sword, he was pushed vertically into the bottom of the stream and let a piece of paper down the river. The blade had to cut it in half.

Extraction of ore

The process of obtaining and processing tamahagane was surrounded by mystery. Only the smiths knew all the secrets of steel making and passed on their art to the heirs. The ore from which the tamahagane was extracted was met near the riverbeds in the form of black iron sand. It was the product of the disintegration of natural deposits. The laborious process of sand enrichment was required, since it contained only about 1% of iron. The rocks were washed with water in canals. Particles of iron settled on the bottom and were delayed by special obstacles.

Process of smelting

A large number of workers were needed to produce steel. The process of obtaining tamahagane occurred in traditional Japanese smelting furnaces. The peculiarity of the technology was that they were constructed of clay and were intended for single use. After the completion of the smelting, the wall had to be destroyed to extract the finished metal. Several helpers blacksmith by burning charcoal and inflating the flame brought the temperature in the oven to 1200-1500 ^o C. After this, a gradual loading of enriched iron sand began. The whole process of smelting took three days. To obtain the right amount of carbon, the weight of burnt charcoal was almost twice the mass of iron sand.

Sorting

As a result of one smelting, they usually received about two tons of steel. In the furnace a metal block of impressive size was formed, and for its extraction clay walls were destroyed. But the ingot was heterogeneous in terms of carbon content. It was necessary to split it into parts and choose the most suitable ones for quality. About a third of the material received was usually marred. In Japan, there are still a number of excessively massive steel blocks that could not be broken down for sorting. They serve as a kind of monuments to the traditional art of smelting metals.

Modern methods

In today's Japan, the production of tamahagane steel continues. The modern production process differs from the old one in that at the stage of ore dressing iron particles are separated from the rock by means of a magnet. This method is used instead of time-consuming washing of sand with water in canals. The era of samurai swords has long ended, but made in Japan kitchen knives from diamond steel are in demand in the world market.

Features of alloy ХВ5

Modern technologies of smelting significantly outperform the ancient methods. Enriched ore is cleaned of slag with lime. The molten iron is removed from the furnace and placed in a centrifuge to improve its structure. Characteristics of diamond steel ХВ5 are improved by adding to it other metals, mainly tungsten. Its exceptional refractoriness requires heating the furnace to a temperature of 3000 ^o C. The addition of this component increases the wear resistance of the XB5 alloy.

Operational advantages

The main characteristic of diamond steel is its hardness. Blades and other products from this alloy can for a long time dispense with sharpening. They have excellent cutting properties and are able not only to process softer metals, but also to remove fine chips from them. Chromium in the composition of alloy ХВ5 protects it from corrosion. But products made of this steel grade are not completely stainless and only with a small degree of resistance to the wet environment.

disadvantages

The high hardness of the material makes it brittle. For example, a diamond can not be scratched, but it is easy to split. The drawbacks of XV5 diamond steel are a consequence of its hardness. Blades made of this alloy require careful handling, because the cutting edge may appear jagged. This problem is typical for any grade of high-carbon tool steel. Sometimes products made of such material are broken when dropped to the floor. Attempts to find the optimal ratio of hardness and brittleness led to the invention of alloys with a reduced carbon content. As an example, we can cite the steel grade H1 produced in Japan. In its composition, only 0.15% of carbon is present. To disadvantages of diamond steel ХВ5 also it is necessary to carry its high cost.

Souvenir Knives

Blades and tools from this alloy have many applications. Often there are souvenir and collection knives from diamond steel ХV5. Such products are usually decorated with engraving of author's work, and their handles are made of valuable wood. Sometimes on the surface of the blade naturally creates whimsical patterns that increase the aesthetic value of the product. The reason for this phenomenon is the uneven distribution of carbon in steel.

Knives for marching conditions

Blades from alloy ХВ5 find practical application on hunting and fishing. Due to their excellent cutting qualities, they allow the extraction to be quickly separated. But reviews about diamond steel from hunters and fishermen do not inspire much optimism. Fragile blades require extremely careful handling. They can easily get damaged and become unusable. In marching conditions, unreliable knives create serious problems if they fail their owners at an inopportune moment. In addition, the stability of chromium tungsten steel to rust leaves much to be desired. Blades made of this material are more suitable for home use.

Handling and storage

If a knife made of chromium-tungsten steel is not used for a long time, its blade should be greased with animal fat. It is not recommended to store the product in sheath. In case of rust, it is necessary to process the blade with sandpaper. After use, it is advisable to wipe the knife dry and lubricate it with grease. Care should be taken when contacting the blade with hard surfaces such as bone, stone, and metal. The blade can crumble from strong pressing or impact. Friability is an inevitable disadvantage of chromium tungsten steel. But it is worth taking into account that the technology of hardening the blade varies among different manufacturers, so the quality of the products may be different.