What is the benefit of annealing heat treatment? In addition to annealing, what other processes are there in the overall heat treatment? -Kehua
There are a total of four processes in the overall heat treatment, including annealing heat treatment. What is the use of annealing heat treatment? What are the other three processes? Friends who don't know this aspect, you can follow Kehua Xiaobian to learn about it and increase your knowledge in this area. The overall heat treatment includes annealing, normalizing, quenching, and tempering. The overall heat treatment is a metal heat treatment process that heats the workpiece as a whole and then cools it at an appropriate rate to change its overall mechanical properties. Annealing, normalizing, quenching and tempering are the four basic processes in the overall heat treatment, which are called 'four fires'. Understand the differences and functions of annealing, normalizing, quenching, and tempering: Annealing is a heat treatment process that heats the workpiece to an appropriate temperature, adopts different holding times according to the material and workpiece size, and then slowly cools with the furnace. The essence is to heat the steel. The pearlite transformation is carried out after austenitization. The purpose is to make the internal structure of the metal reach or close to the equilibrium state, to obtain good process performance and performance, or to prepare the structure for further quenching. The purpose and function of annealing heat treatment annealing: reduce the hardness of steel, improve plasticity, in order to facilitate cutting and cold deformation processing; refine grains, eliminate structural defects caused by forging, welding, etc., homogenize the structural composition of steel, and improve the performance of steel Or prepare for later heat treatment; eliminate internal stress in steel to prevent deformation or cracking. Normalizing is to heat the workpiece to a suitable temperature and then cool it in the air. The effect of normalizing is similar to that of annealing, but the obtained structure is finer. It is often used to improve the cutting performance of materials, and sometimes used for some parts with low requirements. as the final heat treatment. Quenching is to heat the workpiece to a certain temperature on the critical point, keep it for a certain time, and rapidly cool it in a quenching medium such as water, oil or other inorganic salts, organic aqueous solutions, etc., to obtain martensite and (or) bainite structure. heat treatment process. After quenching, the steel becomes hard, but at the same time becomes brittle. Annealing Heat Treatment Kehua Xiaobian thinks that the purpose of quenching is to transform the supercooled austenite into martensite (or bainite) to obtain a martensite (or bainite) structure, and then tempering at different temperatures to obtain required mechanical properties. The quenched workpiece is not allowed to be used directly on site. Usually, it must be tempered 1-2 times or more in real time after that to adjust its structure and stress. Tempering In order to reduce the brittleness of steel parts, the quenched steel parts are kept at an appropriate temperature higher than room temperature but lower than 710 ℃ for a long time, and then cooled. This process is called tempering. The purpose and function of tempering is to reasonably adjust the mechanical properties to make the workpiece meet the requirements of use; to stabilize the structure so that the workpiece does not undergo structural transformation during use, so as to ensure that the size and shape of the workpiece remain unchanged; to reduce or eliminate the internal stress of quenching to reduce Reduce workpiece deformation and prevent cracking. Annealing heat treatment has a great effect, it can reduce the hardness of the steel, improve the plasticity, and is conducive to the later processing deformation. If you are just engaged in this field of work, you can learn more about mechanical knowledge and be prepared.