Alloy metals: description, list and application features

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

Development is identified with improvement. Improving industrial and domestic capabilities is carried out through the use of materials with progressive characteristics. These are, in particular, alloyed metals. Their diversity is determined by the possibility of correcting the quantitative and qualitative composition of alloying elements.

Natural Alloy Steel

The first smelted iron, which differed from its relatives in its properties, was naturally alloyed. Smelted prehistoric meteoric iron contained an increased amount of nickel. It was found in ancient Egyptian burials of 4-5 millennia BC. e., the architectural monument of Qutab Minar in Delhi (5th century) was built from the same. Japanese damask swords were made of iron saturated with molybdenum, and Damascus steel contained tungsten, characteristic of modern high-speed cutting. These were metals, the ore for which was mined from certain places.

Modern production alloys may contain naturally occurring metallic andnon-metallic origin, which are reflected in their characteristics and properties.

Historical path

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

• The simultaneous discovery of more and more new chemical elements pushed researchers to experimental smelting experiments.
• The negative impact of copper on the quality of steel has been established.
• Brass containing 6% iron discovered.

Experiments were carried out in terms of qualitative and quantitative effects on the steel alloy of tungsten, manganese, titanium, molybdenum, cob alt, chromium, platinum, nickel, aluminum and others.

The first industrial production of steel alloyed with manganese was established at the beginning of the 19th century. It has been developed since 1856 as part of the Bessemer smelting process.

Features of doping

Modern capabilities make it possible to smelt alloyed metals of any composition. The basic principles of the technology in question:

1. Components are considered alloying only if they are introduced purposefully and the content of each exceeds 1%.
2. Sulfur, hydrogen, phosphorus are considered impurities. as non-metallicinclusions are used boron, nitrogen, silicon, rarely - phosphorus.
3. Bulk alloying is the introduction of components into a 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 influence of high temperatures.
4. During the process, additives change the crystal structure of the "daughter" material. They can create penetration or exclusion solutions, as well as be placed at the boundaries of metallic and non-metallic structures, creating a mechanical mixture of grains. The degree of solubility of elements in each other plays a big role here.

Alloying components

According to the general classification, all metals are divided into ferrous and non-ferrous. Blacks include iron, chromium and manganese. Non-ferrous 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. Alloy metals include a wide variety of light, heavy, noble and refractory non-ferrous metals, as well as all ferrous ones.

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

Alloy steels

Technologically, the process does not cause difficulties. The range is very wide. Main goals forsteels are as follows:

• Increase strength.
• Improve heat treatment results.
• Increasing corrosion resistance, heat resistance, heat resistance, heat resistance, resistance to aggressive working conditions, service life.

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

Chromium and nickel are the main components that define stainless steel (X18H9T), as well as heat-resistant steel, the operating conditions of which are characterized by high temperatures and shock loads (15X5). Up to 1.5% are used for bearings and friction parts (15HF, SHKH15SG)

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

Silicon and vanadium are elements that increase elasticity in a certain amount and are used to make springs and springs (55C2, 50HFA).

Aluminum is applicable for iron with high electrical resistance (X13Y4).

A significant content of tungsten is typical for high-speed resistant tool steels (R9, R18K5F2). An alloyed metal drill made from this material is much more productive and resistant to triggering than the same tool made from carbon steel.

Alloy steels have entered everyday use. At the same time, the so-called alloys with amazing properties, also obtained by alloying methods, are known. So "wooden steel" contains 1% chromiumand 35% nickel, which determines its high thermal conductivity, characteristic of wood. Diamond also includes 1.5% carbon, 0.5% chromium and 5% tungsten, which characterizes it as especially hard, akin to diamond.

Alloying cast iron

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

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

The technology is complicated by the low melting temperature (on average, up to 1000 ˚C), while for most alloying elements it significantly exceeds this level.

Complex alloying is the most effective for cast irons. At the same time, one should take into account the increased probability of segregation of such castings, the risk of cracking, and casting defects. It is more rational to carry out the technological process in electromagnetic and induction furnaces. A mandatory sequential step is high-quality heat treatment.

Chromium cast irons are characterized by high wear resistance, strength, heat resistance, resistance to aging and corrosion (CH3, CH16). They are used in chemical engineering and in the production of metallurgical equipment.

Cast irons alloyed with silicon are distinguished by high corrosion resistance and resistance to aggressive chemical compounds, although they have satisfactory mechanical properties (ChS13, ChS17). They form parts of chemical equipment, pipelines and pumps.

Heat-resistant cast irons are an example of highly productive complex alloying. They contain ferrous and alloying metals such as chromium, manganese, nickel. They are characterized by high corrosion resistance, wear resistance and resistance to high loads under high temperature conditions - parts of turbines, pumps, engines, chemical industry equipment (ChN15D3Sh, ChN19Kh3Sh).

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

Alloy copper

Used in pure form and as part of copper alloys, which have a wide variety depending on the ratio of basic and alloying elements: brass, bronze, cupronickel, nickel silver and others.

Pure brass - an alloy with zinc - is not alloyed. If it contains alloying non-ferrous metals in a certain amount, it is considered multicomponent. Bronzes are alloys with other metallic constituents,can be tin and not containing tin, are alloyed in all cases. Their quality is improved with the help of Mn, Fe, Zn, Ni, Sn, Pb, Be, Al, P, Si.

Silicon content in copper compounds increases their corrosion resistance, strength and elasticity; tin and lead - determine the anti-friction qualities and positive characteristics regarding machinability; nickel and manganese - components of the so-called wrought alloys, which also have a positive effect on corrosion resistance; iron improves mechanical properties, while zinc improves technological properties.

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 mechanical engineering and instrumentation, in pipelines and heat exchangers.

Aluminum alloying

Used as wrought or cast alloys. Alloyed metals based on it are compounds with copper, manganese or magnesium (duralumins and others), the latter are compounds with silicon, the so-called silumins, while all their possible variants are alloyed with Cr, Mg, Zn, Co, Cu, Si.

Copper increases its ductility; silicon - fluidity and high-quality casting properties; chromium, manganese, magnesium - improve strength, technological properties of workability by pressure and corrosion resistance. Also, B, Pb, Zr,Ti, Bi.

Iron is an undesirable component, but it is used in small quantities in the production of aluminum foil. Silumins are used for casting critical parts and housings in mechanical engineering. Duralumins and aluminum-based stamping alloys are an important raw material for the manufacture of hull elements, including load-bearing structures, in the aircraft industry, shipbuilding and mechanical engineering.

Alloyed metals are used in all areas of industry as those that have improved mechanical and technological characteristics compared to the original material. The range of alloying elements and the capabilities of modern technologies allow for a variety of modifications that expand the possibilities in science and technology.