What is heat treatment? What is its main function?

Heat treatment: A process in which metal materials or workpieces are heated, held at a certain temperature, and then cooled in an appropriate manner to achieve the desired microstructure and properties. Main functions: ① Improve processability to ensure the smooth progress of subsequent processing steps. For example, homogenization annealing can improve hot working properties ； Intermediate annealing can improve cold working properties. ②Improve performance for use and fully utilize the potential of the material. For example, LY12 duralumin, which is widely used in the aviation industry, can see its tensile strength increase from 196 MPa to 392–490 MPa after quenching and aging treatment.

Heat treatment is a comprehensive processing technique in which a material is heated, held at a certain temperature, and then cooled within a specific medium; by altering the structural organization of the material’s surface or interior, its properties can be controlled. Metal heat treatment is one of the important processes in mechanical manufacturing. Compared with other processing methods, heat treatment generally does not change the shape of the workpiece or its overall chemical composition; instead, it enhances or improves the performance of the workpiece by altering its internal microstructure or the chemical composition of its surface. Its feature is improving the internal quality of the workpiece, which is generally not visible to the naked eye. 　　To endow metal workpieces with the desired mechanical, physical, and chemical properties, in addition to the proper selection of materials and various forming processes, heat treatment is often essential. Steel is the most widely used material in the machinery industry. Its microstructure is complex, but it can be controlled through heat treatment; therefore, heat treatment of steel constitutes the main focus of metal heat treatment. Furthermore, metals such as aluminum, copper, magnesium, titanium, and their alloys can also have their mechanical, physical, and chemical properties altered through heat treatment to achieve different performance characteristics. Here is another link: http://bbs.hcbbs.com/viewthread.php?tid=272192&highlight=%C8%C8%B4%A6%C0%ED%CA%D6%B2%E1 The \"Heat Treatment Handbook\" (4th edition), complete set of four volumes, is available for download.

This is the area for exchanging information on production technologies. I think the original poster might not be asking about metal heat treatment, but rather about heat treatment in production processes. Process heat treatment is usually applied to drying equipment such as shell-and-tube dryers. Due to continuous operation, a thick layer of material can accumulate on the tubes of these dryers, affecting heat transfer efficiency. There is a heat treatment method that allows for simple processing: by stopping the feed and raising the temperature rapidly to overheat the tubes, followed by an immediate stop of heating to cool the tubes suddenly. This rapid change in temperature helps to remove the material accumulated on the tubes, thereby cleaning them quickly and ensuring proper heat transfer, without the need to shut down the production line. During heat treatment, attention must be paid to the temperature, which must not exceed the design temperature of the equipment; the time period should also be controlled carefully, so as to prevent the device from stopping due to the cessation of material feeding.

Heat treatment is a comprehensive processing technique in which a material is heated, held at a certain temperature, and then cooled within a specific medium; by altering the structural organization of the material’s surface or interior, its properties can be controlled. It’s complicated anyway~ I can’t explain it clearly myself~ You should check it out by yourself: lol http://baike.baidu.com/view/32682.htm

This is a chemical engineering forum, and I also think the original poster isn’t asking about heat treatment in metal processing, haha.

During the construction of chemical industry static equipment, heat treatment is applied to the welded areas, with the aim of enabling a uniform crystal structure to form between the weld material and the surrounding materials, thereby eliminating stresses

Heat treatment is divided into two main categories: conventional heat treatment and surface heat treatment. Common methods of normal heat treatment include annealing, normalizing, quenching, and tempering, while surface heat treatment includes surface quenching and chemical heat treatment. Chemical heat treatment includes carburizing, nitriding, carbonitriding, chromium plating, titanium plating, aluminum plating, sulfurizing, and more. Heat treatment is a comprehensive processing technique in which a material is heated, held at a certain temperature, and then cooled within a specific medium; by altering the structural organization of the material’s surface or interior, its properties can be controlled. Heat treatment plays two roles in the machining and manufacturing of mechanical parts: ensuring and improving certain properties of the workpiece ； Improve the microstructure and stress state of the blank to facilitate various cold and hot processing operations. 1. Common heat treatment methods and their main application areas. (1) Annealing involves heating the steel component to a temperature 30–50°C above its critical temperature and holding it there for a certain period of time, after which it is cooled slowly (usually by furnace cooling). It is mainly used to eliminate the internal stresses in cast, forged, and welded parts, reduce their hardness to facilitate machining, and refine the metal grains. (2) Normalizing involves heating the steel part above its critical temperature, holding it at that temperature for a certain period of time, and then cooling it with air; the cooling rate is faster than that in annealing. It is mainly used to treat low-carbon and medium-carbon structural steels as well as carburized parts, thereby refining their microstructure, enhancing their strength and toughness, reducing internal stresses, and improving their machinability. (3) Quenching involves heating the steel part to a temperature above its critical point, holding it at that temperature for a certain period of time, and then rapidly cooling it in water, saltwater, or oil (for some materials, in air) in order to achieve high hardness. It is mainly used to increase the hardness and strength limit of steel. However, quenching induces internal stresses that make the steel brittle, so tempering is necessary after quenching. (4) Tempering involves heating a hardened steel part to a temperature below its critical point, holding it at that temperature for a certain period of time, and then cooling it in air or oil. It is mainly used to eliminate brittleness and internal stresses after quenching, thereby improving plasticity and impact toughness. (5) Quenching and tempering: high-temperature tempering after quenching. It is mainly used to endow steel with high toughness and sufficient strength; many important components must undergo quenching and tempering treatment. (6) Surface quenching gives the surface of the part very high hardness and wear resistance, while the core retains its original strength and toughness. It is mainly used to treat the surface of gears. (7) Aging: The steel is heated to ≤120–130°C, held at that temperature for an extended period, and then cooled in the furnace or taken out and cooled in air. It is mainly used to eliminate or reduce the micro-stresses resulting from quenching, prevent deformation and cracking, stabilize the shape and dimensions of the workpiece, and remove the residual stresses from machining.