High frequency quenching production principle and process analysis

What is the principle of high-frequency quenching? This is a very technical problem. This production process is usually used in the production of steel or metal accessories. Quenching uses high-voltage current to generate heat energy through the metal surface, so as to achieve the effect of heating. Next, I will explain to you the principle of high frequency quenching. The principle of high-frequency quenching production: Using the skin effect of the current, a current is formed on the surface of the part to heat the workpiece to achieve different heat treatment states of the core and the surface; according to the current frequency, it is divided into power frequency, intermediate frequency and high frequency. For different hardening depths and workpiece sizes. The depth of high frequency (above 10KHZ) heating is 0.5-2.5mm, which is generally used for the heating of small and medium-sized parts, such as small module gears and small and medium shaft parts. The intermediate frequency (1~10KHZ) heating depth is 2-10mm, which is generally used for the heating of shafts with large diameters and gears with large and medium modules. The depth of power frequency (50HZ) heating and quenching layer is 10-20mm, which is generally used for diathermy of larger-sized parts, and surface quenching of large-diameter parts (diameter Ø300mm or more, such as rolls, etc.). A metal heat treatment process in which a metal workpiece is heated to an appropriate temperature and kept for a period of time, and then immersed in a quenching medium for rapid cooling. Commonly used quenching media are brine, water, mineral oil, air, etc. Quenching can improve the hardness and wear resistance of metal workpieces, so it is widely used in various tools, molds, measuring tools and parts that require surface wear resistance (such as gears, rolls, carburized parts, etc.). Through the combination of quenching and tempering at different temperatures, Kehua can greatly improve the strength, toughness and fatigue strength of the metal, and can obtain the coordination between these properties (comprehensive mechanical properties) to meet different application requirements. In addition, quenching can also make some special properties of steel obtain certain physical and chemical properties, such as quenching to enhance the ferromagnetism of permanent magnet steel, and stainless steel to improve its corrosion resistance. The quenching process is mainly used for steel parts. When the commonly used steel is heated above the critical temperature, all or most of the original structure at room temperature will be transformed into austenite. The austenite is then transformed into martensite by immersing the steel in water or oil for rapid cooling. Compared with other structures in steel, martensite has the highest hardness. The purpose of steel quenching is to transform all or most of its structure into martensite, obtain high hardness, and then temper it at an appropriate temperature to make the workpiece have the desired properties. The rapid cooling during quenching will generate internal stress inside the workpiece, and when it is too large, the workpiece will be twisted and deformed or even cracked. A suitable cooling method must be selected for this purpose. According to the cooling method, Kehua quenching process is divided into four categories: single-liquid quenching, double-medium quenching, martensitic graded quenching and bainite isothermal quenching. High-frequency quenching production Important factors of quenching effect, hardness requirements and detection methods of quenched workpieces: The hardness of quenched workpieces affects the effect of quenching. Quenching workpieces generally use a Rockwell hardness tester to test HRC hardness. Hardened thin steel sheets and case hardened workpieces can test the hardness of HRA. Hardened steel plates with a thickness of less than 0.8mm, shallow surface quenched workpieces and hardened steel rods with a diameter of less than 5mm can be replaced by surface Rockwell hardness testers to test HRN hardness using high-frequency quenching to make many metal fittings, etc. Currently in many factories and construction Personnel or construction teams will use this technology, but quenching also has disadvantages, that is, because the temperature is too high to cool down, some technical measures must be taken.