The so-called vacuum heat treatment is a heat treatment method in which a workpiece is heated to a desired temperature in a vacuum medium of 0.1-0.01 Pa and then cooled in different media at different cooling rates. Vacuum heat treatment is called efficient, energy-saving and pollution-free clean heat treatment in the contemporary heat treatment industry. Vacuum heat treatment parts have a series of advantages such as no oxidation, no decarburization, degassing, degreasing, good surface quality, small deformation, high comprehensive mechanical properties, good reliability (reproducibility, stable life) and so on. Therefore, the vacuum heat treatment has been widely and widely applied at home and abroad, and the popularity of vacuum heat treatment as an important indicator of a country's level of heat treatment technology. Vacuum heat treatment technology is a hot spot for heat treatment process development in the past 40 years, and it is also an important area for today's advanced manufacturing technologies. Vacuum heat treatment technology is a new type of heat treatment technology developed in recent years. It has the characteristics that are urgently needed in the manufacture of molds, for example, to prevent thermal oxidation and decarburization, vacuum degassing or degassing, Eliminates hydrogen embrittlement, thereby increasing the material's plasticity, toughness, and fatigue strength. Vacuum heating is slow, and the temperature difference between the inside and outside of the part is small, which determines the small deformation of the parts caused by the vacuum heat treatment process. In the work of the mold, in addition to requiring the substrate to have a reasonable combination of high enough strength and toughness, its surface properties are critical to the work performance and service life of the mold. The surface treatment technology of the mold is a systematic project to change the shape, chemical composition, structure and stress state of the mold surface by surface coating, surface modification or composite treatment technology to obtain the required surface properties. At present, in the manufacture of molds, the main applications of nitriding, carburizing, and hardened film deposition are more. Because the nitriding technology can form a surface with excellent performance, in order to maintain the excellent characteristics of vacuum heating of workpieces, the choice and formulation of coolant and cooling process are very important. The quenching process of the die mainly uses oil cooling and air cooling, and the nitriding process and die steel Quenching process has a good coordination, at the same time, the temperature of the nitriding is low, after the nitriding without the need for intense cooling, mold deformation is minimal, therefore, the surface of the mold is to strengthen the nitriding technology earlier, but also the most widely used. In vacuum heat treatment of molds, vacuum oil quenching, vacuum air quenching and vacuum tempering are mainly used. For the working surface of the mold, which is no longer machined after the heat treatment, vacuum tempering, particularly vacuum-quenched workpieces, is used after quenching. It can improve the mechanical properties related to the surface quality such as fatigue properties, surface brightness, and corrosion resistance. Wait. High Speed Viscose Yarn King Spool Winder Machine High Speed Horn Type Bobbin Winder,Spun Yarn Rewinding Machine,Viscose Staple Winding Machine,High Speed Coil Winding Machine Ningbo Yongfu Textile Machinery Co., Ltd. , https://www.yfwinders.com