Steel ingots heat treatment is an important part of the entire steel production process, as it is performed in order to ensure that steel parts are hardened, tempered and strengthened. The most common method used to heat treat steel ingots is through the use of induction heating. Induction heating relies on a coil of copper wire wrapped around the outside of the ingot. An alternating current passes through the coils, creating an internal magnetic field that causes the molecules of the steel to move around and vibrate rapidly, resulting in a rapid increase in temperature.
The temperature to which an ingot is heated is dependent upon the type of steel and the desired end result. Mild steel is heated to around 1650 degrees Fahrenheit, while tool steel and high carbon steel is heated to between 1700 and 2000 degrees Fahrenheit. After the ingot is heated, a period of soaking is required in order to ensure that the heat is evenly distributed within the ingot. After the soaking period is complete, the ingot is then cooled via a quenching process.
Quenching serves multiple purposes. First, it rapidly reduces the amount of heat held in the metal, which serves to harden the steel and reduce the risk of part cracking and distortion. Secondly, it also helps to improve the tensile strength of the metal by allowing atoms to align themselves faster and more uniformly. Finally, a quench also helps to reduce the risk of corrosion, as the rapid temperature change creates a surface that is not suitable for corrosion agents.
Once the quenching process is complete, the ingot is heat treated a second time, known as tempering. This process serves to reduce the hardness of the metal and increase its ductility. This allows the metal to better tolerate sudden stresses and impacts, while also increasing its elasticity. Tempering is usually done at lower temperatures, usually between 500 and 1600 degrees Fahrenheit.
Steel ingot heats treatment is an important process in the manufacturing of high quality steel parts. Through the proper management of heat and temperature, steel ingots can be hardened, tempered, and strengthened to create metal parts that are durable and high-performing. Careful attention must be paid during each of the stages of the process in order to consistently produce quality parts every time.
