At what temperature does iron melt?
Metals melt, as a rule, at a very high temperature, which can reach more than 3 thousand degrees. Although some of them can be melted at home, such as lead or tin. But mercury is melted at a temperature of minus 39 degrees.
This cannot be achieved at home. Melting point is one of the important indicators of the production of not only the metal itself, but also its alloys. When smelting raw materials, specialists take into account other physical and chemical properties of the ore and metal.
Iron is a chemical element that is number 26 on the periodic table. It is one of the most abundant elements in the entire solar system. According to research materials, the Earth's core contains approximately 79−85% of this substance . There is also a large amount of it in the earth's crust, but it is inferior to aluminum.
In its pure form, the metal is white with a slightly silvery tint. It is plastic, but the impurities present in it can determine its physical properties. Reacts to a magnet.
Iron is present in water. In river waters its concentration is approximately 2 mg/l of metal. In sea water its content can be a hundred or even a thousand times lower.
Iron oxide is the main form that is mined and found in nature. Iron oxide can be located in the uppermost part of the earth's crust and be a component of sedimentary formations.
An element in twenty-sixth place on the periodic table can have several oxidation states. It is they who determine its geochemical feature of being in a certain environment. In the Earth's core, the metal is present in a neutral form.
Mining
There are several ores containing iron. However, the following are mainly used as raw materials for iron production in industry:
- magnesite ore;
- goethite ore;
- hematite ore.
And also the following types of ore are often found:
- lellingitis;
- siderite;
- marcasite;
- ilmenite;
- is violent.
There is also a mineral called melanterite . It is used primarily in the pharmaceutical industry. It consists of green, fragile crystals with a glassy sheen. Medicines containing ferum are produced from it.
The main deposit of this metal is South America, namely Brazil.
Iron melting and required temperature
The melting point of a metal is the minimum temperature at which it changes from solid to liquid. At the same time, it remains practically unchanged in volume.
Metal can be produced from ore in various ways, but the most basic of them is blast furnace . In addition to blast furnace, iron smelting is also used by roasting crushed ore with an admixture of clay. From the resulting mixture, pellets are formed, which are processed in a furnace followed by reduction with hydrogen. Next, the iron is melted in an electric furnace.
The melting point of iron is very high. For a technically pure element it is +1539 °C. This substance contains an impurity - Sulfur, which can only be extracted in liquid form. Without impurities, pure material is obtained by electrolysis of metal salts.
Classification of metals by melting point
Different metals can turn liquid at different temperatures. As a result, a certain classification is distinguished. They are divided as follows:
- Low-fusibility elements are those elements that can become liquid even at temperatures below 600 degrees. These include zinc, tin, lead, etc. They can be melted even at home - you just need to heat them up using a stove or soldering iron. Such types have found application in technology and electronics. They are used to connect metal elements and move electric current. Tin melts at 232 degrees, and zinc at 419 degrees.
- Medium-melting - elements that begin to melt at temperatures from six hundred to one thousand six hundred degrees. These elements are used mainly for building elements and metal structures, that is, when creating fittings, slabs and building blocks. This group includes: iron, copper, aluminum. The melting point of aluminum is relatively low and is 660 degrees. But iron begins to turn into a liquid state only at a temperature of 1539 degrees. It is one of the most common metals used in industry, especially in the automotive industry. However, iron is susceptible to corrosion, that is, rust, so it requires special surface treatment. It must be coated with paint or drying oil, and moisture must not be allowed to enter.
- Refractory are materials that melt and become liquid at temperatures above 1600 degrees. This group includes tungsten, titanium, platinum, chromium, etc. They are used in the nuclear industry and for some machine parts. They can be used for melting other metals, making high-voltage wires or wire. Platinum can be melted at 1769 degrees, and tungsten at 3420 °C.
Cast iron melting temperature
The only element that is in a liquid state under normal conditions is mercury. Its melting point is minus 39 degrees and its vapors are poisonous, so it is used only in laboratories and closed containers.
Source: https://steelfactoryrus.com/pri-kakoy-temperature-plavitsya-zhelezo/
What is the melting point of iron
Metals melt, as a rule, at a very high temperature, which can reach more than 3 thousand degrees. Although some of them can be melted at home, such as lead or tin. But mercury is melted at a temperature of minus 39 degrees.
This cannot be achieved at home. Melting point is one of the important indicators of the production of not only the metal itself, but also its alloys. When smelting raw materials, specialists take into account other physical and chemical properties of the ore and metal.
Iron and its properties
Iron is a chemical element that is number 26 on the periodic table. It is one of the most abundant elements in the entire solar system. According to research materials, the Earth's core contains approximately 79−85% of this substance . There is also a large amount of it in the earth's crust, but it is inferior to aluminum.
In its pure form, the metal is white with a slightly silvery tint. It is plastic, but the impurities present in it can determine its physical properties. Reacts to a magnet.
Iron is present in water. In river waters its concentration is approximately 2 mg/l of metal. In sea water its content can be a hundred or even a thousand times lower.
Iron oxide is the main form that is mined and found in nature. Iron oxide can be located in the uppermost part of the earth's crust and be a component of sedimentary formations.
An element in twenty-sixth place on the periodic table can have several oxidation states. It is they who determine its geochemical feature of being in a certain environment. In the Earth's core, the metal is present in a neutral form.
Boiling and melting points of metals
The table shows the melting point of metals tmelt , their boiling point tk at atmospheric pressure, the density of metals ρ at 25°C and thermal conductivity λ at 27°C.
The melting point of metals, as well as their density and thermal conductivity are given in the table for the following metals: actinium Ac, silver Ag, aluminum Al, gold Au, barium Ba, beryllium Be, bismuth Bi, calcium Ca, cadmium Cd, cobalt Co, chromium Cr, cesium Cs, copper Cu, iron Fe, gallium Ga, hafnium Hf, mercury Hg, indium In, iridium Ir, potassium K, lithium Li, magnesium Mg, manganese Mn, molybdenum Mo, sodium Na, niobium Nb, nickel Ni, neptunium Np , osmium Os, protactinium Pa, lead Pb, palladium Pd, polonium Po, platinum Pt, plutonium Pu, radium Ra, rubidium Pb, rhenium Re, rhodium Rh, ruthenium Ru, antimony Sb, tin Sn, strontium Sr, tantalum Ta, technetium Tc, thorium Th, titanium Ti, thallium Tl, uranium U, vanadium V, tungsten W, zinc Zn, zirconium Zr.
According to the table, it can be seen that the melting point of metals varies over a wide range (from -38.83°C for mercury to 3422°C for tungsten). Metals such as lithium (18.05°C), cesium (28.44°C), rubidium (39.3°C) and other alkali metals have a low positive melting point.
The most refractory metals are the following: hafnium, iridium, molybdenum, niobium, osmium, rhenium, ruthenium, tantalum, technetium, tungsten. The melting point of these metals is above 2000°C.
Here are examples of the melting point of metals widely used in industry and everyday life:
- melting point of aluminum 660.32 °C;
- copper melting point 1084.62 °C;
- melting point of lead 327.46 °C;
- melting point of gold 1064.18 °C;
- melting point of tin 231.93 °C;
- the melting point of silver is 961.78 °C;
- The melting point of mercury is -38.83°C.
Rhenium Re has the maximum boiling point of the metals presented in the table - it is 5596°C. Also, metals belonging to the group with a high melting point have high boiling points.
The density of the metals in the table ranges from 0.534 to 22.59 g/cm 3 , that is, the lightest metal is lithium, and the heaviest metal is osmium. It should be noted that osmium has a density greater than that of uranium and even plutonium at room temperature.
The thermal conductivity of metals in the table varies from 6.3 to 427 W/(m deg), thus the worst conductor of heat is a metal such as neptunium, and the best heat-conducting metal is silver.
Melting point of steel
A table of melting temperature values for common grades of steel is presented. Steels for castings, structural, heat-resistant, carbon and other classes of steels are considered.
The melting point of steel ranges from 1350 to 1535°C. The steels in the table are arranged in order of increasing melting point.
Melting point of steel - table- Volkov A.I., Zharsky I.M. Large chemical reference book. - M: Soviet School, 2005. - 608 p.
- Kazantsev E.I. Industrial furnaces. Reference manual for calculations and design.
- Physical quantities. Directory. A. P. Babichev, N. A. Babushkina, A. M. Bratkovsky and others; Ed. I. S. Grigorieva, E. Z. Meilikhova. - M.: Energoatomizdat, 1991. - 1232 p.
Each metal or alloy has unique properties, including its melting point. In this case, the object passes from one state to another, in a particular case, it becomes liquid from solid. To melt it, you need to apply heat to it and heat it until the desired temperature is reached. At the moment when the desired temperature point of a given alloy is reached, it may still remain in a solid state. As exposure continues, it begins to melt.
Source: https://vi-pole.ru/pri-kakoj-temperature-plavitsja-zhelezo.html
At what temperature does metal melt?
Each metal or alloy has unique properties, including its melting point. In this case, the object passes from one state to another, in a particular case, it becomes liquid from solid. To melt it, you need to apply heat to it and heat it until the desired temperature is reached. At the moment when the desired temperature point of a given alloy is reached, it may still remain in a solid state. As exposure continues, it begins to melt.
- How the process works
- Depending on the degree at which metals melt, they are divided into:
- Characteristics table
- Among the most commonly used elements in everyday life, the melting point indicators are as follows:
Mercury has the lowest melting point - it melts even at -39 °C, tungsten has the highest - 3422 °C. For alloys (steel and others) it is extremely difficult to determine the exact figure. It all depends on the ratio of the components in them. For alloys it is written as a numerical interval.
How the process works
Elements, whatever they are: gold, iron, cast iron, steel or any other, melt approximately the same. This occurs due to external or internal heating. External heating is carried out in a thermal furnace. For internal applications, resistive heating is used, passing an electric current or induction heating in a high-frequency electromagnetic field . The impact is approximately the same.
When heating occurs , the amplitude of thermal vibrations of molecules increases. Structural lattice defects appear , accompanied by the rupture of interatomic bonds. The period of lattice destruction and accumulation of defects is called melting.
Depending on the degree at which metals melt, they are divided into:
- low-melting - up to 600 °C: lead, zinc, tin;
- medium-melting - from 600 °C to 1600 °C: gold, copper, aluminum, cast iron, iron and most of all elements and compounds;
- refractory - from 1600 °C: chromium, tungsten, molybdenum, titanium.
Depending on what the maximum degree is, the melting apparatus is selected. It should be stronger the stronger the heating.
The second important value is the boiling degree. This is the parameter at which liquids begin to boil. As a rule, it is twice the melting point. These values are directly proportional to each other and are usually given at normal pressure.
If the pressure increases, the amount of melting also increases. If the pressure decreases, then it decreases.
Characteristics table
Metals and alloys are an indispensable basis for forging , foundry, jewelry and many other areas of production. Whatever the craftsman does ( gold jewelry , cast iron fences, steel knives or copper bracelets) , in order to work correctly, he needs to know the temperatures at which this or that element melts.
To find out this parameter, you need to refer to the table. In the table you can also find the boiling degree.
Among the most commonly used elements in everyday life, the melting point indicators are as follows:
- aluminum - 660 °C;
- copper melting point - 1083 °C;
- melting point of gold - 1063 °C;
- silver - 960 °C;
- tin - 232 °C.
Tin is often used for soldering, since the temperature of a working soldering iron is exactly 250–400 degrees;
- lead - 327 °C;
- melting point of iron - 1539 °C;
- the melting point of steel (an alloy of iron and carbon) is from 1300 °C to 1500 °C.
It varies depending on the saturation of the steel with components;
- melting point of cast iron (also an alloy of iron and carbon) - from 1100 °C to 1300 °C;
- mercury - -38.9 °C.
As is clear from this part of the table, the most fusible metal is mercury, which at positive temperatures is already in a liquid state.
The boiling point of all these elements is almost twice, and sometimes even higher than the melting point. For example, for gold it is 2660 °C, for aluminum - 2519 °C , for iron - 2900 °C, for copper - 2580 °C, for mercury - 356.73 °C.
For alloys such as steel, cast iron and other metals, the calculation is approximately the same and depends on the ratio of components in the alloy.
The maximum boiling point of metals is rhenium - 5596 ° C. The highest boiling point is for the most refractory materials.
There are tables that also indicate the density of metals . The lightest metal is lithium, the heaviest is osmium. Osmium has a higher density than uranium and plutonium when viewed at room temperature.
Light metals include: magnesium, aluminum, titanium. Heavy metals include most common metals: iron, copper, zinc, tin and many others. The last group is very heavy metals, these include: tungsten, gold, lead and others.
Another indicator found in the tables is the thermal conductivity of metals . Neptunium is the worst conductor of heat, and the best metal in terms of thermal conductivity is silver. Gold, steel, iron, cast iron and other elements are in the middle between these two extremes. Clear characteristics for each can be found in the required table.
Source: https://respect-kovka.com/pri-kakoy-temperature-plavitsya-metall/
Physical characteristics, composition and features of iron metal
Iron is the first most important and widespread structural material. It has been known since ancient times, and its properties are such that when they learned to smelt iron in significant quantities, the metal replaced all other alloys. The age of iron has arrived and, judging by the scope of its application, this time will not end soon. This article will tell you what the specific density of iron is and what its melting point is in its pure form.
Iron is a typical metal, and it is chemically active. The substance reacts at normal temperature, and heating or increasing humidity significantly increases its reactivity. Iron corrodes in air, burns in an atmosphere of pure oxygen, and in the form of fine dust can ignite in air.
Pure iron is inherently malleable, but the metal is very rare in this form. In fact, iron means an alloy with small proportions of impurities - up to 0.8%, which is characterized by the softness and malleability of a pure substance. Alloys with carbon - steel, cast iron, stainless steel - are important for the national economy.
Iron is characterized by polymorphism: there are as many as 4 modifications, differing in structure and lattice parameters:
- α-Fe - exists from zero to 69 C. It has a body-centered cubic lattice and is ferromagnetic, that is, it retains magnetization in the absence of an external magnetic field. 69 C – Curie point for metal;
- from 69 to +917 C β-Fe appears. It differs from the α phase only in lattice parameters. Almost all physical properties are preserved with the exception of magnetic ones: iron becomes paramagnetic, that is, it loses the ability to magnetize and is drawn into a magnetic field. Metallurgy does not consider the β-phase as a separate modification. Since the transition does not affect significant physical characteristics;
- in the range from 917 to 1394 C there is a γ-modification, which is characterized by a face-centered cubic lattice;
- at temperatures above +1394 C, the δ phase appears, which is characterized by a body-centered cubic lattice.
At high pressure, as well as when the metal is doped with certain additives, an ε-phase with a hexagonal close-packed lattice is formed.
The temperature of phase transitions changes noticeably when doped with the same carbon. Actually, the very ability of iron to form so many modifications serves as the basis for processing steel in different temperature conditions. Without such transitions, the metal would not have become so widespread.
Now it’s time for the properties of the metal iron.
This video tells about the structure of iron:
Iron is a fairly light, moderately refractory metal, silver-gray in color. Reacts easily with dilute acids and is therefore considered a medium activity element. In dry air, the metal is gradually covered with an oxide film, which prevents further reaction.
But at the slightest humidity, instead of a film, rust appears - loose and heterogeneous in composition. Rust does not prevent further corrosion of iron. However, the physical properties of the metal, and, most importantly, its alloys with carbon, are such that, despite the low corrosion resistance, the use of iron is more than justified.
Next, you will find out what the density of iron is (in kg per m3) in comparison, for example, with copper or aluminum.
Mass and density
The molecular weight of iron is 55.8, which indicates the relative lightness of the substance. What is the density of iron? This indicator is determined by the phase modification:
- α-Fe – 7.87 g/cubic. cm at 20 C, and 7.67 g/cc. cm at 600 C;
- The γ-phase has an even lower density - 7.59 g/cc at 1000C;
- The density of the δ-phase is 7.409 g/cc.
With increasing temperature, the density of iron naturally decreases.
Now let's find out what the melting point of iron is in Celsius, comparing it, for example, with copper or cast iron.
Temperature Range
The metal is moderately refractory, which means a relatively low temperature of change in the state of aggregation:
- melting point – 1539 C;
- boiling point – 2862 C;
- Curie temperature, that is, loss of the ability to magnetize, is 719 C.
It is worth keeping in mind that when they talk about the melting or boiling point, they are dealing with the δ-phase of the substance.
This video will tell you about the physical and chemical properties of iron:
Iron and its alloys are so widespread that, although they began to be used later than, for example, copper and bronze, they have become unique standards. When comparing metals, they point to iron: stronger than steel, 2 times softer than iron, and so on.
The characteristics are given for a metal containing small proportions of impurities:
- hardness on the Mohs scale – 4–5;
- Brinell hardness – 350–450 MN/sq. m. Moreover, chemically pure iron has a higher hardness – 588–686;
Strength indicators are extremely dependent on the amount and nature of impurities. This value is regulated by GOST for each grade of alloy or pure metal. Thus, the compressive strength for unalloyed steel is 400–550 MPa. When hardening this grade, the tensile strength increases to 700 MPa.
- the impact strength of the metal is 300 MN/sq m;
- yield strength –100 MN/sq. m.
We will learn further about what is needed to determine the specific heat capacity of iron.
Heat capacity and thermal conductivity
Like any metal, iron conducts heat, although its performance in this area is low: in terms of thermal conductivity, the metal is inferior to aluminum - 2 times less, and copper - 5 times.
Thermal conductivity at 25 C is 74.04 W/(m K). The value depends on temperature;
- at 100 k the thermal conductivity is 132 [W/(m.K)];
- at 300 K – 80.3 [W/(m.K)];
- at 400 – 69.4 [W/(m.K)];
- and at 1500 – 31.8 [W/(m.K)].
Important:
- The coefficient of thermal expansion at 20 C is 11.7·10-6.
- The heat capacity of a metal is determined by its phase structure and depends rather complexly on temperature. With an increase to 250 C, the heat capacity slowly increases, then increases sharply until the Curie point is reached, and then begins to decrease.
- The specific heat capacity in the temperature range from 0 to 1000C is 640.57 J/(kg K).
Electrical conductivity
Iron conducts current, but not nearly as well as copper and silver. The electrical resistivity of the metal under normal conditions is 9.7·10-8 ohm·m.
Since iron is ferromagnetic, its performance in this area is more significant:
- saturation magnetic induction is 2.18 Tesla;
- magnetic permeability – 1.45.106.
The toxicity of iron is discussed next.
The metal does not pose a danger to the human body. The processes of steel production and the manufacture of iron products can be dangerous, but only due to the high temperatures and those additives that are used in the production of various alloys. Iron waste - scrap metal - poses a danger to the environment, but it is quite moderate, since the metal rusts in air.
Iron is not biologically inert, therefore it is not used as a material for prosthetics. However, in the human body this element plays one of the most important roles: a violation in the absorption of iron or an insufficient amount of the latter in the diet guarantees anemia at best.
Iron is absorbed with great difficulty - 5–10% of the total amount supplied to the body, or 10–20% if there is a deficiency.
- The usual daily requirement for iron is 10 mg for men and 20 mg for women.
- Toxic dose – 200 mg/day.
- Lethal – 7–35 g. It is almost impossible to obtain such an amount of iron, so iron poisoning is extremely rare.
Iron is a metal whose physical characteristics, particularly strength, can be significantly altered by mechanical processing or the addition of very small amounts of alloying elements. This feature, combined with the availability and ease of metal extraction, makes iron the most popular structural material.
A specialist will tell you even more about the properties of iron in the video below:
Source: http://stroyres.net/metallicheskie/vidyi/chyornyie/zhelezo/fizicheskie-harakteristiki.html
Iron smelting at home - Metals, equipment, instructions
Technique to the question Tell me, how can you, roughly speaking, melt iron at home? The best answer given by the author Djin If it is iron (Fe), then it is impossible. Where will you find temperatures over 1500 degrees at home?
in the oven, muffle, high frequency currents, autogenous, electrode, I don’t know what kind of iron you have and how many tons
Depends on what kind. Lead can be placed on a spoon above the candles. Of course, if there is not enough of it, for example, steel that is no larger than a coin, you can try to float it with a gas burner. (these are sold) It seems the outlet temperature is about 750g. This is not enough for
At home, no way! 1500 degrees can theoretically be obtained if there is gas in the apartment (gas stove), but the iron will melt and immediately turn into scale (iron oxide).
Well, in general, there are 2 methods for the home: A stove using high-frequency currents and a gas burner\acetylene one definitely melts\
You can try connecting a graphite rod to a 12 volt DC source. And then think about it.
How to melt iron 10 grams at home
how to melt iron 10 grams at home
- iron melts at a temperature of 1539C, you can try to set fire to the house and throw a piece of iron into the thick of it, it might melt
- Go to the housing office to see the welders.
- Using an oxygen-acetylene torch (used in car service centers and construction sites). or build a HDTV.
- The most interesting way to melt iron is with thermite :-)) This is done like this: Take aluminum powder (If you have silver paint, use it) and mix it with potassium permangonate (potassium permanganate, this is a good oxidizing agent) 1:1. The combustion temperature will be sufficient even to melt the frying pan. This mixture is ignited with a good charge of match powder or something better, you just can’t light it with a match. This thing burns very powerfully, so take care of safety carefully, do the experiment on the street, do not stand nearby (the column of sparks and fire will be more than a meter). In fact, when thermite is used for welding, for example, rails, it seems that iron oxide is mixed with aluminum, which, when melted, is reduced into pure iron, flows down and thus welds the rails. But as I understand it, you need to melt a certain piece of iron? Then my recipe is what you need. And the New Year is just around the corner, you can melt the metal and at the same time you can set off fireworks :-)))))))
- Iron? Fe? Or some other metal? Lead, tin - please. Iron - no way. Other temperatures are needed.
- you need to look at what temperature the autonomous Rothenberger gas burners develop, maybe they’ll give you a ride, they’re sold here in Ob. About the arc - I dabbled once, although the voltage was 12V at a current of about 10A. I melted a drop of iron so that it melted into the glass, but something more massive could not be heated - the temperature gradient would be too great, it would be barely red at the edges, and it would evaporate and boil near the electrodes. Unless you build an electrolyzer and heat it with a hydrogen flame, you just need to clarify the temperature.
How to smelt iron
When manufacturing metal structures in a home workshop, sometimes you have to deal with the need to melt metal. An electric oven can help you cope with this task. Such a device is capable of melting many metals, including iron. By making a furnace with your own hands, you will significantly expand your capabilities in iron processing.
— electric melting furnace;
Source: https://spb-metalloobrabotka.com/plavka-zheleza-v-domashnih-usloviyah/
Melting point of metals. The most refractory and fusible metal:
Almost all metals are solids under normal conditions. But at certain temperatures they can change their state of aggregation and become liquid. Let's find out what is the highest melting point of metal? Which is the lowest?
Melting point of metals
Most of the elements in the periodic table are metals. There are currently approximately 96 of them. They all require different conditions to turn into liquid.
The heating threshold of solid crystalline substances, above which they become liquid, is called the melting point. For metals it varies within several thousand degrees. Many of them turn into liquid with relatively high heat. This makes them a common material for making pots, pans and other kitchen utensils.
Silver (962 °C), aluminum (660.32 °C), gold (1064.18 °C), nickel (1455 °C), platinum (1772 °C), etc. have average melting points. There is also a group of refractory and low-melting metals. The first need more than 2000 degrees Celsius to turn into liquid, the second need less than 500 degrees.
Low-melting metals usually include tin (232 °C), zinc (419 °C), and lead (327 °C). However, some of them may have even lower temperatures. For example, francium and gallium melt in the hand, but cesium can only be heated in an ampoule, because it ignites with oxygen.
The lowest and highest melting temperatures of metals are presented in the table:
| Refractory | Low-melting | ||
| Tungsten | 3422 °C | Mercury | -38.87 °C |
| Rhenium | 3186 °C | Gallium | 26.79 °C |
| Tantalum | 3017 °C | France | 27 °C |
| Osmium | 3033 °C | Cesium | 28.5 °C |
| Molybdenum | 2623 °C | Rubidium | 39.31 °C |
| Niobium | 2477°C | Potassium | 63.5 °C |
| Iridium | 2466 °C | Sodium | 97.8 °C |
Tungsten
Tungsten metal has the highest melting point. Only the nonmetal carbon ranks higher in this indicator. Tungsten is a light gray shiny substance, very dense and heavy. It boils at 5555 °C, which is almost equal to the temperature of the Sun's photosphere.
At room conditions, it reacts weakly with oxygen and does not corrode. Despite its refractoriness, it is quite ductile and can be forged even when heated to 1600 °C. These properties of tungsten are used for incandescent filaments in lamps and picture tubes and electrodes for welding. Most of the mined metal is alloyed with steel to increase its strength and hardness.
Tungsten is widely used in the military sphere and technology. It is indispensable for the manufacture of ammunition, armor, engines and the most important parts of military vehicles and aircraft. It is also used to make surgical instruments and boxes for storing radioactive substances.
Mercury
Mercury is the only metal whose melting point is minus. In addition, it is one of two chemical elements whose simple substances, under normal conditions, exist in the form of liquids. Interestingly, the metal boils when heated to 356.73 °C, and this is much higher than its melting point.
It has a silvery-white color and a pronounced shine. It evaporates already at room conditions, condensing into small balls. The metal is very toxic. It can accumulate in human internal organs, causing diseases of the brain, spleen, kidneys and liver.
Mercury is one of the seven first metals that man learned about. In the Middle Ages it was considered the main alchemical element. Despite its toxicity, it was once used in medicine as part of dental fillings, and also as a cure for syphilis. Now mercury has been almost completely eliminated from medical preparations, but it is widely used in measuring instruments (barometers, pressure gauges), for the manufacture of lamps, switches, and doorbells.
Alloys
To change the properties of a particular metal, it is alloyed with other substances. Thus, it can not only acquire greater density and strength, but also reduce or increase the melting point.
An alloy can consist of two or more chemical elements, but at least one of them must be a metal. Such “mixtures” are very often used in industry, because they make it possible to obtain exactly the qualities of materials that are needed.
The melting point of metals and alloys depends on the purity of the former, as well as on the proportions and composition of the latter. To obtain low-melting alloys, lead, mercury, thallium, tin, cadmium, and indium are most often used.
Those containing mercury are called amalgams. A compound of sodium, potassium and cesium in a ratio of 12%/47%/41% becomes a liquid already at minus 78 ° C, an amalgam of mercury and thallium - at minus 61 ° C.
The most refractory material is an alloy of tantalum and hafnium carbides in 1:1 proportions with a melting point of 4115 °C.
Source: https://www.syl.ru/article/374078/temperatura-plavleniya-metallov-samyiy-tugoplavkiy-i-legkoplavkiy-metall
At what temperature does cast iron melt?
Today, cast iron is considered one of the most common metals. Parts for machinery and industrial equipment, building materials and much more are made from it. Before casting, you need to know the melting point of cast iron.
Types of cast iron
There are several types of cast iron. Various alloying impurities are added to it, which change the characteristics of the solid material. For this, aluminum, chromium, vanadium or nickel are used. In addition to them there are other impurities. The parameters of finished products directly depend on the composition of the alloy. Varieties:
- Gray cast iron. It is considered the most popular type. The composition contains 2.5% carbon, which is a particle of graphite or perlite. Has a high strength index. Gray cast iron is used to make parts that can withstand constant loads. These can be gears, housing parts, bushings.
- White cast iron. The carbon contained in the composition is carbide particles. A white mark remains on the fracture of the material, which corresponds to the name. carbon on average more than 3%. A fragile and brittle type of material, which is why it is used only in static parts.
- Half-hearted. Combines the characteristics of the two previous types of cast iron. Graphite and carbide particles saturate the metal with carbon. Its content is from 3.5 to 4.2%. Wear-resistant material used in mechanical engineering. Withstands constant friction.
- Malleable cast iron. It is obtained from the second type of material, after annealing. The alloy contains carbon in the form of ferrite particles. Its amount is about 3.5%. Like half-shaft, it is used for the manufacture of parts in mechanical engineering.
To obtain a high-strength material, graphite particles are processed so that they take on a spherical shape and fill the crystal lattice. Magnesium, calcium or cerium are added to the alloy.
Thermal properties of cast iron
The characteristics of a metal depend on its thermal properties. They change when treated with high and low temperatures. Directly depend on the composition of the alloy.
Heat capacity
Heat capacity is the processing of metal with heat. Heats up until the temperature of the workpiece rises by one Kelvin. This indicator depends on the presence of additional components in the alloy and temperature. If it is high, then the heat capacity will be greater. Average heat capacity:
- Hard metal - 1 cal/cm3G.
- Molten material - 1.5 cal/cm3G.
From these indicators the ratio of heat capacity and volume of the substance is calculated.
Thermal conductivity
This parameter determines how well a material can conduct heat energy. It depends not only on the components in the alloy, but also on the structure of the metal. The thermal conductivity for a solid material is higher than for a molten one. For different grades of steel, this indicator varies within 0.08–0.13 cal/cm sec oC.
Thermal diffusivity
This physical quantity reflects the ability of a material to change body temperature. When calculating, it is necessary to take into account the following indicators:
- Thermal conductivity range for different grades of cast iron. Applicable to solid material.
- For liquid metal - 0.03 cm2/sec.
Additionally, the heat capacity indicator is taken into account.
Melting temperature
Cast iron is considered the best metal for smelting. Its high fluidity rate and low shrinkage allow it to be used more effectively in casting. Below are the boiling points for different types of this metal in degrees Celsius:
- Gray cast iron - melting point reaches 1260 degrees. When pouring into molds it rises to 1400.
- White - melts at 1350 degrees. Poured into molds at 1450.
The melting rates of cast iron are 400 degrees lower than those of steel. This reduces energy costs when processing cast iron.
The influence of chemical elements on the properties of metal
To understand how impurities affect the characteristics and properties of cast iron, it is necessary to understand the structure of its individual types:
- White - The form of carbon in this variety is carbide. White color is visible at the break. It is considered a brittle and brittle material that is rarely used in industry without additives.
- Gray cast iron. The graphite plates in this material saturate it with carbon. To use the material in the production of parts for industrial equipment, the shape of the grains is changed by melting.
- Malleable - The graphite grains in this type of metal have the appearance of flakes.
High-strength cast iron is obtained by adding magnesium to the alloy. To improve the characteristics of this metal, impurities are used.
Impurities
Each impurity added to iron and carbon changes the properties of the finished material. The influence of additives on the quality of cast iron:
- Magnesium. Allows you to make spherical grains in the material. This increases the strength and hardness of the workpiece.
- Manganese. Slows down the graphitization process. The metal is whiter at fractures.
- Silicon. Increases graphitization of the material. The maximum amount of silicon in the workpiece is 3.5%. The strength indicator depends on its quantity.
- Sulfur. The amount of this impurity is reduced to improve fluidity.
- Phosphorus. Has virtually no effect on the graphitization process. Improves fluidity. By adding phosphorus to the alloy, wear resistance and strength are improved.
Alloy materials can be added to cast iron.
Self-smelting technology
Knowing at what temperature cast iron melts, you can carry out independent smelting. However, this is a costly and time-consuming process. It is impossible to make a high-quality casting without special equipment.
First of all, you need to equip a separate room with good ventilation. The smelting process is carried out in a furnace. The best option is a blast furnace. It can be used to process large volumes of consumables (iron ore). The fuel used is coke. However, this is industrial equipment that requires special conditions of use.
Induction furnaces are used in our own workshops.
The raw materials are melted in crucibles. During the smelting process, it is necessary to use flux, which creates a low-melting slag. Once the metal is molten, the craftsman pours it into sand or metal molds. Cast iron casting. DIY melting furnace from A to Z “Cupola furnace”.
The melting point of cast iron varies slightly depending on the type of material and the impurities it contains. It is extremely difficult to process this metal at home. It is necessary to equip the room, take care of ventilation and fire safety. After preparation, install the furnace and other equipment for smelting.
At what temperature does cast iron melt? Link to main publication
Source: https://metalloy.ru/stal/plavlenie-chuguna
Melting point and basic properties of iron, classification of metals
Metals melt, as a rule, at a very high temperature, which can reach more than 3 thousand degrees. Although some of them can be melted at home, such as lead or tin. But mercury is melted at a temperature of minus 39 degrees.
This cannot be achieved at home. Melting point is one of the important indicators of the production of not only the metal itself, but also its alloys. When smelting raw materials, specialists take into account other physical and chemical properties of the ore and metal.
Iron is a chemical element that is number 26 on the periodic table. It is one of the most abundant elements in the entire solar system. According to research materials, the Earth's core contains approximately 79−85% of this substance . There is also a large amount of it in the earth's crust, but it is inferior to aluminum.
In its pure form, the metal is white with a slightly silvery tint. It is plastic, but the impurities present in it can determine its physical properties. Reacts to a magnet.
Iron is present in water. In river waters its concentration is approximately 2 mg/l of metal. In sea water its content can be a hundred or even a thousand times lower.
Iron oxide is the main form that is mined and found in nature. Iron oxide can be located in the uppermost part of the earth's crust and be a component of sedimentary formations.
An element in twenty-sixth place on the periodic table can have several oxidation states. It is they who determine its geochemical feature of being in a certain environment. In the Earth's core, the metal is present in a neutral form.
Temperature at which iron melts
Two modifications of the iron crystal lattice
Several polymorphic modifications have been established for iron, of which the high-temperature modification - γ-Fe (above 906°) forms a lattice of a face-centered cube of the Cu type (a = 3.63), and the low-temperature modification - the α-Fe lattice of a centered cube of the α-Fe type (a = 2.86).
Depending on the heating temperature, iron can be found in three modifications, characterized by different crystal lattice structures:
- In the temperature range from the lowest to 910 ° C - a-ferrite (alpha ferrite), which has a crystal lattice structure in the form of a centered cube;
- In the temperature range from 910 to 1390°C - austenite, the crystal lattice of which has the structure of a face-centered cube;
- In the temperature range from 1390 to 1535 ° C (melting point) - d-ferrite (delta ferrite). The crystal lattice of d-ferrite is the same as that of a-ferrite. The only difference between them is the different (larger for d-ferrite) distances between the atoms.
When liquid iron is cooled, primary crystals (crystallization centers) appear simultaneously at many points in the cooled volume. With subsequent cooling, new crystalline cells are built around each center until the entire supply of liquid metal is exhausted. The result is a granular structure of the metal. Each grain has a crystal lattice with a certain direction of its axes.
With subsequent cooling of solid iron, during the transitions of d-ferrite to austenite and austenite to a-ferrite, new crystallization centers may appear with a corresponding change in grain size
PROPERTIES
In its pure form under normal conditions it is a solid. It has a silver-gray color and a pronounced metallic luster. The mechanical properties of iron include its level of hardness on the Mohs scale. It is equal to four (average). Iron has good electrical and thermal conductivity.
The last feature can be felt by touching an iron object in a cold room.
Because this material conducts heat quickly, it removes most of it from your skin in a short period of time, which is why you feel cold. If you touch, for example, wood, you will notice that its thermal conductivity is much lower.
The physical properties of iron include its melting and boiling points. The first is 1539 degrees Celsius, the second is 2860 degrees Celsius. We can conclude that the characteristic properties of iron are good ductility and fusibility. But that's not all. Also, the physical properties of iron include its ferromagnetism.
What it is? Iron, whose magnetic properties we can observe in practical examples every day, is the only metal that has such a unique distinctive feature. This is explained by the fact that this material is capable of magnetization under the influence of a magnetic field.
And after the end of the action of the latter, the iron, the magnetic properties of which have just been formed, remains a magnet for a long time. This phenomenon can be explained by the fact that in the structure of this metal there are many free electrons that are able to move.
Source: https://ostwest.su/instrumenty/temperatura-pri-kotoroj-plavitsja-zhelezo.php/
Table of melting temperatures of various metals, and at how many degrees they melt
Each metal and alloy has its own unique set of physical and chemical properties, not least of which is the melting point. The process itself means the transition of a body from one state of aggregation to another, in this case, from a solid crystalline state to a liquid one.
To melt a metal, it is necessary to apply heat to it until the melting temperature is reached. With it, it can still remain in a solid state, but with further exposure and increased heat, the metal begins to melt. If the temperature is lowered, that is, some of the heat is removed, the element will harden.
The highest melting point among metals belongs to tungsten : it is 3422Co, the lowest is mercury: the element melts at - 39Co. As a rule, it is not possible to determine the exact value for alloys: it can vary significantly depending on the percentage of components. They are usually written as a number interval.
How it happens
Melting of all metals occurs approximately the same way - using external or internal heating. The first is carried out in a thermal furnace; for the second, resistive heating is used by passing an electric current or induction heating in a high-frequency electromagnetic field. Both options affect the metal approximately equally.
As the temperature increases the amplitude of thermal vibrations of molecules , and structural defects in the lattice arise, expressed in the growth of dislocations, jumping of atoms and other disturbances. This is accompanied by the rupture of interatomic bonds and requires a certain amount of energy. At the same time, a quasi-liquid layer forms on the surface of the body. The period of lattice destruction and defect accumulation is called melting.
Metal separation
Depending on their melting point, metals are divided into:
- Low-melting: they need no more than 600Co. This is zinc, lead, hang, tin.
- Medium-melting: melting point ranges from 600Со to 1600Со. These are gold, copper, aluminum, magnesium, iron, nickel and more than half of all elements.
- Refractory: requires temperatures above 1600°C to make the metal liquid. These include chromium, tungsten, molybdenum, titanium.
Depending on the melting temperature, the melting apparatus is also selected . The higher the indicator, the stronger it should be. You can find out the temperature of the element you need from the table.
Another important quantity is the boiling point. This is the value at which the process of boiling liquids begins; it corresponds to the temperature of saturated steam that forms above the flat surface of the boiling liquid. It is usually almost twice the melting point.
Both values are usually given at normal pressure. directly proportional to each other .
- As the pressure increases, the amount of melting increases.
- As the pressure decreases, the amount of melting decreases.
Table of refractory metals and alloys (over 1600C o)
Source: https://stanok.guru/stanki/metallorezhuschiy-stanok/temperatura-plavleniya-raznyh-metallov-v-tablice.html
At what temperature does iron melt, the melting point of ferrous, non-ferrous metals and some alloys
In the metallurgical industry, one of the main areas is the casting of metals and their alloys due to the low cost and relative simplicity of the process. Molds with any shape and various dimensions can be cast, from small to large; It is suitable for both mass and customized production.
Casting is one of the oldest areas of working with metals, and begins around the Bronze Age: 7-3 millennium BC. e. Since then, many materials have been discovered, leading to advancements in technology and increased demands on the foundry industry.
Nowadays, there are many directions and types of casting, differing in technological process. One thing remains unchanged - the physical property of metals to pass from a solid to a liquid state, and it is important to know at what temperature the melting of different types of metals and their alloys begins.
Metal melting process
This process refers to the transition of a substance from a solid to a liquid state. When the melting point is reached, the metal can be in either a solid or liquid state; further increase will lead to the complete transition of the material into a liquid.
The same thing happens during solidification - when the melting point is reached, the substance will begin to transition from a liquid to a solid state, and the temperature will not change until complete crystallization.
It should be remembered that this rule applies only to pure metal. Alloys do not have a clear temperature boundary and undergo state transitions in a certain range :
- Solidus is the temperature line at which the most fusible component of the alloy begins to melt.
- Liquidus is the final melting point of all components, below which the first alloy crystals begin to appear.
It is impossible to accurately measure the melting point of such substances; the point of transition of states is indicated by a numerical interval.
Depending on the temperature at which metals begin to melt, they are usually divided into :
- Low-melting, up to 600 °C. These include tin, zinc, lead and others.
- Medium melting, up to 1600 °C. Most common alloys, and metals such as gold, silver, copper, iron, aluminum.
- Refractory, over 1600 °C. Titanium, molybdenum, tungsten, chromium.
There is also a boiling point - the point at which the molten metal begins to transition into a gaseous state. This is a very high temperature, typically 2 times the melting point.
Effect of pressure
The melting temperature and the equal solidification temperature depend on pressure, increasing with its increase. This is due to the fact that with increasing pressure the atoms come closer to each other, and in order to destroy the crystal lattice they need to be moved away. At increased pressure, greater thermal energy is required and the corresponding melting temperature increases.
There are exceptions when the temperature required to transform into a liquid state decreases with increased pressure. Such substances include ice, bismuth, germanium and antimony.
Melting point table
It is important for anyone involved in the metallurgical industry, whether a welder, foundry worker, smelter or jeweler, to know the temperatures at which the materials they work with melt. The table below shows the melting points of the most common substances.
Table of melting temperatures of metals and alloys
In addition to the melting table, there are many other supporting materials. For example, the answer to the question what is the boiling point of iron lies in the table of boiling substances. In addition to boiling, metals have a number of other physical properties, such as strength.
Strength of metals
In addition to the ability to transition from a solid to a liquid state, one of the important properties of a material is its strength - the ability of a solid body to resist destruction and irreversible changes in shape. The main indicator of strength is the resistance that occurs when a pre-annealed workpiece breaks. The concept of strength does not apply to mercury because it is in a liquid state. The designation of strength is accepted in MPa - Mega Pascals.
metal strength groups :
- Fragile. Their resistance does not exceed 50MPa. These include tin, lead, soft-alkaline metals
- Durable, 50−500 MPa. Copper, aluminum, iron, titanium. Materials of this group are the basis of many structural alloys.
- High strength, over 500 MPa. For example, molybdenum and tungsten.
Metal strength table
The most common alloys in everyday life
As can be seen from the table, the melting points of elements vary greatly even among materials commonly found in everyday life.
Thus, the minimum melting point of mercury is -38.9 °C, so at room temperature it is already in a liquid state. This explains why household thermometers have a lower mark of -39 degrees Celsius: below this indicator, mercury turns into a solid state.
The most common solders in household use contain a significant percentage of tin, which has a melting point of 231.9 °C, so most solders melt at the operating temperature of the soldering iron 250−400 °C.
In addition, there are low-melting solders with a lower melt limit, up to 30 °C, and are used when overheating of the materials being soldered is dangerous. For these purposes, there are solders with bismuth, and the melting of these materials lies in the range from 29.7 - 120 °C.
Melting of high-carbon materials, depending on alloying components, ranges from 1100 to 1500 °C.
The melting points of metals and their alloys are in a very wide temperature range, from very low temperatures (mercury) to several thousand degrees. Knowledge of these indicators, as well as other physical properties, is very important for people who work in the metallurgical field. For example, knowledge of the temperature at which gold and other metals melt will be useful to jewelers, foundries and smelters.
Source: https://chebo.biz/tehnologii/temperatura-plavleniya-tsvetnyh-i-chernyh-metallov.html
