Alloyed metals: description, list and application features

Development is identified with perfection. Improvement of industrial and domestic opportunities is achieved through the use of materials with progressive characteristics. This, in particular, is doped metals. Their diversity is determined by the possibilities of correcting the quantitative and qualitative composition of the alloying elements.

Natural alloy steel

The first smelted iron, which in its properties differed from its relatives, was naturally-alloyed. The melted prehistoric meteorite gland contained an increased amount of nickel. He was found in ancient Egyptian burials 4-5 millennium BC. E., From the same built a monument of architecture Kutab Minar in Delhi (V century). Japanese bulat swords were made of iron, saturated with molybdenum, and damask steel contained tungsten, characteristic of the modern high-speed. These were metals, the ore for which was extracted from certain places.

Alloys of modern production can contain natural components of metallic and non-metallic origin, which are reflected in their characteristics and properties.

Historical path

The foundation for the development of alloying was laid by the foundation of the crucible method of steel melting in Europe in the 18th century. In a more primitive version crucibles were used in ancient times, including for smelting Damascus and Damascus steel. In the early 18th century, this technology was improved on an industrial scale and allowed to adjust the composition and quality of the source material.

• The simultaneous discovery of more and more new chemical elements, pushed the researchers to experimental experiments on smelting.
• The negative influence of copper on the quality of steel is established.
• The brass containing 6% of iron is open.

Experiments were carried out from the point of view of the qualitative and quantitative effect on the steel alloy of tungsten, manganese, titanium, molybdenum, cobalt, chromium, platinum, nickel, aluminum and others.

The first industrial production of steel, alloyed with manganese, was established at the beginning of the XIX century. It has been developed since 1856 within the framework of the Bessemer process of smelting.

Features of alloying

Modern capabilities allow melting alloyed metals of any composition. Basic principles of the technology in question:

1. Components are considered to be doping only if they are introduced purposefully and the content of each exceeds 1%.
2. Sulfur, hydrogen, phosphorus are considered impurities. As nonmetallic inclusions, boron, nitrogen, silicon, and rarely phosphorus are used.
3. Volumetric alloying is the introduction of components into molten substance within the framework of metallurgical production. Surface is a method of diffusion saturation of the surface layer with the necessary chemical elements under the action of high temperatures.
4. During the process of addition, the crystal structure of the "daughter" material is changed. They can create penetration or exclusion solutions, as well as be placed on the boundaries of metal and non-metallic structures, creating a mechanical mixture of grains. A great role here is played by the degree of solubility of the elements in each other.

Alloying components

According to the general classification, all metals are divided into black and color. Black refers to iron, chrome and manganese. Colored are divided into light (aluminum, magnesium, potassium), heavy (nickel, zinc, copper), noble (platinum, silver, gold), refractory (tungsten, molybdenum, vanadium, titanium), light, rare-earth and radioactive. Doping metals include a significant variety of light, heavy, noble and refractory colored, and also all black.

Depending on the ratio of these elements and the bulk of the alloy, the latter are divided into low-alloyed (3%), medium-alloyed (3-10%) and high-alloyed (more than 10%).

Alloy Steel

Technologically, the process does not cause complications. The assortment is very wide. The main objectives for steels are as follows:

• Strengthening strength.
• Improving the results of heat treatment.
• Increased corrosion resistance, heat resistance, heat resistance, heat resistance, resistance to aggressive operating conditions, service life.

The main components are black alloying and refractory metals, which include Cr, Mn, W, V, Ti, Mo, as well as colored Al, Ni, Cu.

Chromium and nickel are the main components that determine stainless steel (X18N9T), as well as heat-resistant, the operating conditions of which are characterized by high temperatures and shock loads (15x5). In an amount up to 1.5% are used for bearings and friction parts (15ХФ, ШХ15СГ)

Manganese is a fundamental component of wear-resistant steels (110G13L). In small quantities, promotes deoxidation, reducing the concentration of phosphorus and sulfur.

Silicium and vanadium are elements that in a certain amount increase elasticity and are used for making springs and springs (55С2, 50ХФА).

Aluminum is suitable for iron with a large electrical resistance (X13O4).

A significant content of tungsten is characteristic for high-speed stable tool steels (P9, P18K5F2). A doped metal drill made of such material is much more productive and resistant to tripping than the same tool made of carbon steel.

Alloyed steel is included in daily use. At the same time, so-called alloys with surprising properties are known, also obtained by doping methods. So "wooden steel" contains 1% chromium and 35% nickel, which determines its high thermal conductivity, characteristic of wood. Diamond also includes 1.5% of carbon, 0.5% of chromium and 5% of tungsten, which characterizes it as particularly hard, akin to diamond.

Alloying of cast iron

Cast iron differs from steels with a significant carbon content (from 2.14 to 6.67%), high hardness and corrosion resistance, but insignificant strength. In order to expand the range of demonstration properties and applications, it is alloyed with chromium, manganese, aluminum, silicium, nickel, copper, tungsten, vanadium.

In connection with the special characteristics of this iron-carbon material, its alloying is a more complicated process than for steel. Each of the components affects the transformation of the forms of carbon in it. Thus, manganese contributes to the formation of "correct" graphite, which increases the strength. The introduction of others results in the transition of carbon to a free state, bleaching of cast iron and reduction of its mechanical properties.

The technology is complicated by a low melting point (on average, up to 1000 ˚С), whereas for most alloying elements it considerably exceeds this level.

The most effective for cast iron complex alloying. At the same time, it is necessary to take into account the increased likelihood of liquation of such castings, the risk of cracking, casting defects. To carry out the technological process more rationally in electromagnetic and induction furnaces. An obligatory consecutive stage is qualitative heat treatment.

Chromium cast iron is characterized by high wear resistance, strength, heat resistance, resistance to aging and corrosion (ЧХ3, ЧХ16). They are used in chemical engineering and in the production of metallurgical equipment.

Cast irons doped with silicon are distinguished by high corrosion resistance and resistance to the influence of aggressive chemical compounds, although satisfactory mechanical properties (ChS13, ChS17). Form the details of chemical equipment, pipelines and pumps.

An example of highly productive complex alloying are heat-resistant cast irons. They contain in their composition black and alloying metals, such as chromium, manganese, nickel. They are characterized by high resistance to corrosion, wear resistance and resistance to high loads under high-temperature conditions - parts of turbines, pumps, engines, chemical equipment (CHN15D3SH, CHN19X3SH).

An important component is copper, which is used in conjunction with other metals, while increasing the casting characteristics of the alloy.

Alloyed copper

Used in its pure form and in the composition of copper alloys, which have a wide variety, depending on the ratio of the basic and alloying elements: brass, bronze, cupronickel, non-silicon, and others.

A pure brass - an alloy with zinc - is not alloyed. If it contains alloying non-ferrous metals in a certain amount - it is considered to be multicomponent. Bronzes are alloys with other metal components, they can be tin and do not contain tin, they are alloyed in all cases. Improve their quality by using Mn, Fe, Zn, Ni, Sn, Pb, Be, Al, P, Si.

The silicon content in copper compounds increases their corrosion resistance, strength and elasticity; Tin and lead - determine the antifriction properties and positive characteristics of machinability by cutting; Nickel and manganese are constituents of so-called deformable alloys, which also have a positive effect on corrosion resistance; Iron improves mechanical properties, and zinc - technological.

They are used in electrical engineering, as the main raw material for the manufacture of various wires, material for the manufacture of critical parts for chemical equipment, in machine building and instrument making, in pipelines and heat exchangers.

Aluminum Alloying

Used in the form of deformable or cast alloys. Alloyed metals on its basis are compounds with copper, manganese or magnesium (duralumin and others), the latter are compounds with silicium, the so-called silumins, with all their possible variants doped with Cr, Mg, Zn, Co, Cu, and Si.

Copper increases its plasticity; Silicon - fluidity and quality foundry properties; Chromium, manganese, magnesium - improve strength, technological properties of machinability and corrosion resistance. Also, B, Pb, Zr, Ti, Bi can be taken as alloying components that promote resistance to aging and to aggressive working conditions.

Iron - an undesirable component, but in small quantities used for the production of aluminum foil. Silumin used for casting critical parts and housings in engineering. Duralumin and die-cast aluminum alloys are an important raw material for the manufacture of hull elements, including power structures, in aircraft building, shipbuilding and machine building.

Alloyed metals are involved in all spheres of industry as those that have increased mechanical and technological characteristics, in comparison with the raw material. The assortment of alloying elements and the capabilities of modern technologies make it possible to produce various modifications that expand the possibilities in science and technology.