In the case of alloying elements, it can be distinguished, essentially, from their role in terms of their role as carbide, austenite, or ferrite or other specific purpose. Each element of the alloy, proportional to the mass percentage of the element, creates special properties in steel. In the case of simultaneous use of several different alloying elements, the properties of the steel can be exacerbated. Of course, there are also alloys that each of its alloying elements, in contrast to its monopoly effect, along with other alloying elements, not only does not create the properties required in steel, but acts completely different. The presence of alloying elements is a necessary condition for the steel properties that can be achieved by performing different machining and heat treatment steps.
Alloy and corresponding elements that have an important impact on steel include:
| Al | Melting point 658 ° C | 1- Aluminum |
This metal is one of the strongest deoxidization and denitridization elements, which has a very good effect on the sensitivity of steel aging. The low consumption of this element contributes to the fine-grained structure of the crystalline structure of steel. Because this metal with nitrogen creates high-strength nitrides, it is one of the important elements in nitrified steel. Aluminum increases the burn and flack resistance of steel, and this is one of the important elements of alloying in flack-resistant ferrite steels. With aluminum alloys (surface aluminizing), steel can be resistant against flacking. The crystalline region becomes much tighter with the addition of aluminum.
Aluminum results in a dramatic increase in the strength of the deresidual force, and this metal is one of the important alloying elements in permanent magnesium alloys, which is a bond of iron, nickel, cobalt and aluminum.
| AS | Melting point 817 ° C | 2- Arsenic |
This element makes the sphere thinner and damages the properties of the steel, because it causes a strong detachment like phosphorus. How to eliminate this detachment by performing intrusive annealing is far more difficult than phosphorus, which increases revers embrittlement, reduces toughness and reduces the ability of welding.
| B | Melting point 2300 ° C | 3- Born |
Since this element plays an important role in the absorption of neutrons, it is an important element in the alloy of steels used in protective equipment and controllers of nuclear power plants. By adding the element to the CrNi 18/8 austenitic steels, due to the hardness, segregation, offset yield strength and rigidity are increased, while simultaneously, corrosion resistance is decreased.
The segregation caused by the addition of a boron element improves the strength properties of high temperature resistant austenitic steels.
It also improves the hardness of the structural steels and increases the brain strength of the carbureted steel. Reducing the steel welding ability due to the presence of this element should be considered.
| Be | Melting point 1280 ° C | 4- Beryllium |
Spiral springs used in the clock building are made of copper-beryllium alloys, which can withstand a greater number of beats than spiral springs made of spring steel. Nickel-Beryllium alloys are highly resistant to corrosion and are very useful in the construction of surgical instruments.
This element will narrow the scope of Y. With this metal, it’s hard to come up with a segregation that also reduces the toughness of the steel. The other properties of this element are deoxidation and the desire to combine with sulfur.
| C | Melting point 1280 ° C for graphite | 5- Carbon |
Carbon is one of the most important and most effective alloying elements in steel. Any non-alloy steel along with the carbon element will also contain other alloying elements, such as silicon, manganese, phosphorus and sulfur, which are unwittingly formed during steel production. Adding other alloying elements to steel properties, or the increase of manganese and silicon, transform steel into alloyed steel. With increasing carbon content, its strength and hardness increase, while increasing the relative length of steel, forging ability, welding ability, and machining ability (with cutting tools) are decreased. The carbon element practically has no effect on the corrosion resistance of water, acids and hot gases.
| Ca | Melting point 850 ° C | 6- Calcium |
Application of this element with silicon is viewed as a deoxidizing agent. Calcium increases the resistance to flake of electrical elements.
| Ce | Melting point 775 ° C | 7- Cerium |
Due to its strong deoxidization and desulfurization properties, it has a cleansing effect, and is furthermore used in conjunction with elements such as lanthanum, neodymium, praseodymium and other rare-earth metals as ” misch metal “.
The presence of this element in high-alloyed steels enhances the heat-sealable formability and improves the resistance of the refractory flake.
| Co | Melting point is 1492 degrees Celsius | 8- Cobalt |
This element is not carbide maker, at high temperatures, it prevents the growth of crystalline grain, and improve the return resistance and greatly strengthens the steel’s hardness, which is why it can not be used as an alloying element in steels – high speed, – hot work, – heat-resistant, and – High temperature.
The presence of cobalt improves the formation of graphite in steel, as well as the high increases of magnetic induction residue, residual force and thermal conductivity, which is why this metal is considered as a basic element in high-value permanent magnets of steel.
Cobalt, under the bombardment of the neutron, forms a radioactive isotope, thus not suitable for many nuclear reactors.
