After vacuum vacuum carburizing heat treatment process, we can reasonably control the formation of carbides in the ball head, ensure the metallographic structure of the workpiece, and there is no reticulated carbide in the microstructure. 3. The various indicators and service life of the workpiece have reached the 5772 standard.
The permeation structure of the ball head portion, the hardness of the microstructure of the 250 4 quality inspection needle body after carburizing heat treatment is as follows: 0.50, outer circle, 0.60, seat surface. 0.401; the ball has penetrated. There is no continuous reticulated carbide in the ball head part, and the carburized martensite and retained austenite in the carburized layer in other parts of the needle valve body are equivalent to the level 3 of the 8 Ding 9730 standard, and the surface of the finished workpiece is not Decarburization or other abnormal tissue.
The data obtained from the test are in full compliance with the technical requirements for the needle body in the 519730 standard. Also. Martensite after carburizing is austempered. The heat treatment deformation of the needle valve body is effectively reduced, which facilitates the subsequent cold working, which is described above. The 18,8 steel needle valve body is subjected to heat treatment such as vacuum pulse type carburizing and normalizing martensite austempering and tempering. Qualified mechanical properties and optimum metallographic structure can be obtained; the deformation of the part can be effectively controlled to ensure the processing precision of the product, and the yield of the product is improved from 85 to 96. Moreover, good performance and long use are obtained. life.
The influence of water pressure on the local frequency bonfire of machine tool guides Ye Rongjia Anhui Huangshan City Huizhou District Weinan Machine Tool Plant, Huangshan, Anhui 245061, China, the bed rails of the 5025 million milling machine 1 use self-made high-hearted fire machine. The quenching and quenching machine is relatively mobile, and the school is 2.8. The electrical parameters are 7 yang = 13 to 7; 7 slots = 7. Day = 2.0 grid =0. 4 quenching process is quenching temperature 880, 900. Continuous water spray cooling; stop heating and continue to spray water 58 to close the cooling water Since the return, 1Schenifnflxidv, iidenfX5025milHngmachiiir practice we found that sometimes the same process parameters are used. The resulting quenching hardness is not stable enough. In the case of only the 58060 test, each type 1 type 5 Leeb hardness tester is provided. In the case of eliminating the influence of various factors such as the electrical parameter material sensor magnetizer. It was found that the cooling water pressure was unstable due to the pipe. When the water pressure drops to 0.1, for example, 1. The quenching and cooling are not sufficient, and the measured hardness values ​​are all less than the specified value of 6401. For this, we added the Taiwanese road to increase the vomiting. The water is increased by 1; reaching 1225, quenching, and the cooling rate is greatly improved. After quenching, the measured hardness reaches 780 800. The plane deformation and bending of the guide rail reaches 0.50.65. At the same time, the subsequent grinding of the guide rail is more difficult due to the hardness. After adjusting the water pressure to 0.15 PCT, about 3, the hardness of the guide rail after quenching is 660 Hu 0 B is more reasonable and moderate, the plane of the guide rail is deformed. Can meet the temperature requirements of self-tempering.
In the process parameters of the machine tool guide surface induction hardening. Cooling water pressure is a factor that cannot be ignored. The water pressure is low. The amount of water is small. The cooling rate is low. Will cause insufficient hardness. A soft spot appears on the workpiece surface. Soft belt. But if the water pressure is high. The amount of water is large, the workpiece is cooled, and almost no heat is transferred from the core to the quenching zone, and the self-tempering of the workpiece cannot be achieved. If the internal stress during quenching is not eliminated, it is used when loading. The guide rail still has a tendency to deform and bend, which affects the geometric precision stability of the machine guide rail. At the same time, the quenching cooling rate is too high under high water pressure. The hardness is high. Quench cracks can also occur. Therefore, in determining the process parameters of the high-frequency quenching of the rail surface. The cooling water pressure must be determined within a reasonable range. The cooling of the heating surface is controlled on the premise of meeting the hardness requirements. The residual heat of the heart is transmitted to the quenching zone to achieve the purpose of self-tempering, so as to reduce the tendency of deformation and cracking. Improve the geometric accuracy of the guide rail
(Finish)
7 Speed Hand Mixer,7 Speed Beater,7 Speed Mixer,Hand Mixer 7 Speed
Jiangmen Sanxin Appliances Co.,Ltd , https://www.sanxinfty.com