{"id":21406,"date":"2022-09-19T09:38:23","date_gmt":"2022-09-19T01:38:23","guid":{"rendered":"https:\/\/www.meetyoucarbide.com\/?p=21406"},"modified":"2022-09-19T09:39:36","modified_gmt":"2022-09-19T01:39:36","slug":"4-key-points-you-may-need-to-know-about-cryogenic-treatment-process","status":"publish","type":"post","link":"https:\/\/www.meetyoucarbide.com\/it\/4-key-points-you-may-need-to-know-about-cryogenic-treatment-process\/","title":{"rendered":"4 Punti chiave che potresti dover sapere sul processo di trattamento criogenico"},"content":{"rendered":"
Cryogenic treatment usually adopts liquid nitrogen cooling, which can cool the workpiece to below – 190 \u2103. The microstructure of the treated material changes at low temperature, and some properties are improved. Cryogenic treatment was first proposed by the former Soviet Union in 1939. It was not until the 1960s that the United States applied the cryogenic treatment technology to the industry and began to use it mainly in the aviation field. In the 1970s, it expanded to the machinery manufacturing field.<\/p>\n\n\n\n
According to different cooling methods, it can be divided into liquid method and gas method. The liquid method means that the material or workpiece is directly immersed in liquid nitrogen to cool the workpiece to liquid nitrogen temperature, and the workpiece is kept at this temperature for a certain period of time, then it is taken out and heated to a certain temperature. It is difficult to control the speed of temperature rise and fall in this way, which has a large thermal impact on the workpiece and is generally believed to be likely to cause damage to the workpiece. Cryogenic equipment is relatively simple, such as liquid nitrogen tank.<\/p>\n\n\n\n
The gas principle is to cool by the gasification latent heat of liquid nitrogen (about 199.54kJ\/kg) and the heat absorption of low-temperature nitrogen. The gas method can make the cryogenic temperature reach – 190 \u2103, so that the cryogenic nitrogen can contact the materials. Through convection heat exchange, the nitrogen can be vaporized in the cryogenic box after being ejected from the nozzle. The workpiece can be cooled by the latent heat of gasification and the heat absorption of cryogenic nitrogen. By controlling the input of liquid nitrogen to control the cooling rate, the cryogenic treatment temperature can be automatically adjusted and accurately controlled, and the thermal shock effect is small, so is the possibility of cracking.<\/p>\n\n\n\n
At present, the gas method is widely recognized by researchers in its application, and its cooling equipment is mainly a programmable cryogenic box with controllable temperature. Cryogenic treatment can significantly improve the service life, wear resistance and dimensional stability of ferrous metals, nonferrous metals, metal alloys and other materials, with considerable economic benefits and market prospects.<\/p>\n\n\n\n
The cryogenic technology of cemented carbide was first reported in the 1980s and 1990s. Mechanical Technology<\/em> of Japan in 1981 and Modern Machine Shop<\/em> of the United States in 1992 reported that the performance of cemented carbides was significantly improved after cryogenic treatment. Since the 1970s, the research work on cryogenic treatment abroad has been fruitful. The former Soviet Union, the United States, Japan and other countries have successfully used cryogenic treatment to improve the service life of tools and dies, wear resistance of workpieces and dimensional stability.<\/p>\n\n\n\n