Hardening and tempering steel is done through a process of heating, quenching and reheating steel. The purpose is to increase the level of hardness and the strength of the steel.Know More
Steel contains carbon, and the amount of carbon determines whether or not it can be hardened. Steel with low concentrations of carbon cannot be hardened because there is insufficient carbon to change the crystalline structure. However, high carbon steel can be hardened and tempered.
To harden the steel, the metal is heated to very high temperatures. After heating the steel higher than its critical temperature, the metal is cooled fast through a process called quenching. This involves dipping the heated metal into water, oil, or any other liquid to rapidly lower its temperature.
Since steel contains carbon along with other metals, the heating of the alloy above its critical temperature causes the carbon and the metals to go into solid solution together. When this solid solution is cooled rapidly through quenching, the solution “freezes” and preserves the micro structure obtained during the heating process, thus making the steel harder. This also makes the steel more brittle, which is why it has to be tempered to maintain the strength of the alloy.
Tempering is the process of reheating the steel to a relatively lower temperature compared to the temperature used for hardening. The reheating allows for the precipitation of the carbon in the steel. Depending on the strength desired in the final product, the temperature and duration for which the steel is tempered can be controlled.Learn more about States of Matter
The specific heat capacity of steel is 452 Joules per kilogram Kelvin, or 0.108 calories per gram Kelvin. This value is based on room temperature and atmospheric pressure. Specific heat capacity is defined as the heat energy needed to raise the temperature of one kilogram of a material by 1 degree Kelvin.Full Answer >
The melting point of mild steel, or low carbon steel, is usually 2,600 degrees Fahrenheit, or 1,427 degrees Celsius. Mild steel is one of the most commonly used types of industrial steel, and it consists of an alloy of steel and carbon.Full Answer >
Condensation is the name of the process through which gas turns into a liquid. Three common states of matter exist: solids, liquids and gases. Matter, however, can change its state with the addition or subtraction of energy. The energy is usually in the form of heat.Full Answer >
The process of a gas changing to a liquid is called condensation, and for condensation to take place, the environment has to reach maximum vapor pressure, generally through a lowering of temperature in the case of the water cycle. Because pressure varies inversely with temperature, as temperature decreases, pressure goes up, causing the gas molecules to move with progressively less kinetic energy. Eventually, liquid vapor and droplets form, and the gas begins to condense.Full Answer >