1 Material selection
The gears should be of the appropriate material according to the working conditions used. The choice of gear material has a direct impact on the machining performance and service life of the gear.
Generally, the gears are made of medium carbon steel (such as 45 steel) and low and medium carbon alloy steels, such as 20Cr, 40Cr, 20CrMnTi.
38CrMoAlA nitrided steel can be used for the important gears, and cast iron, cloth bakelite or nylon can also be used for the non-transmission gears.
2 heat treatment of gears
In the gear processing, two heat treatment processes are arranged according to different purposes:
1) Heat treatment of the blank: Pre-heat treatment or normalizing and tempering is arranged before and after the processing of the tooth blank. The main purpose is to eliminate residual stress caused by forging and roughing, improve the machinability of the material and improve the comprehensive mechanical properties.
2) Tooth surface heat treatment: After the tooth shape processing, in order to improve the hardness and wear resistance of the tooth surface, heat treatment processes such as carburizing and quenching, high frequency induction heating quenching, carbonitriding and nitriding are often performed.
3 gear blank
The blank form of the gears mainly consists of bars, forgings and castings. Bars are used for gears that are small in size, simple in construction, and low in strength. When the gear is required to have high strength, wear resistance and impact resistance, the forgings are often used, and the gears having a diameter larger than 400-600 mm are commonly used for casting blanks. In order to reduce the amount of machining, the gears can be directly cast for large-size and low-precision gears. For small-sized and complex gears, precision casting, pressure casting, precision forging, powder metallurgy, hot rolling and cold extrusion can be used. The process produces a tooth blank with gear teeth to increase labor productivity and save raw materials.
The gears should be of the appropriate material according to the working conditions used. The choice of gear material has a direct impact on the machining performance and service life of the gear.
Generally, the gears are made of medium carbon steel (such as 45 steel) and low and medium carbon alloy steels, such as 20Cr, 40Cr, 20CrMnTi.
38CrMoAlA nitrided steel can be used for the important gears, and cast iron, cloth bakelite or nylon can also be used for the non-transmission gears.
2 heat treatment of gears
In the gear processing, two heat treatment processes are arranged according to different purposes:
1) Heat treatment of the blank: Pre-heat treatment or normalizing and tempering is arranged before and after the processing of the tooth blank. The main purpose is to eliminate residual stress caused by forging and roughing, improve the machinability of the material and improve the comprehensive mechanical properties.
2) Tooth surface heat treatment: After the tooth shape processing, in order to improve the hardness and wear resistance of the tooth surface, heat treatment processes such as carburizing and quenching, high frequency induction heating quenching, carbonitriding and nitriding are often performed.
3 gear blank
The blank form of the gears mainly consists of bars, forgings and castings. Bars are used for gears that are small in size, simple in construction, and low in strength. When the gear is required to have high strength, wear resistance and impact resistance, the forgings are often used, and the gears having a diameter larger than 400-600 mm are commonly used for casting blanks. In order to reduce the amount of machining, the gears can be directly cast for large-size and low-precision gears. For small-sized and complex gears, precision casting, pressure casting, precision forging, powder metallurgy, hot rolling and cold extrusion can be used. The process produces a tooth blank with gear teeth to increase labor productivity and save raw materials.
Centrifuge tubes are used in laboratory centrifuges, machines that spin samples in order to separate solids out of liquid chemical solutions. The centrifuge tubes can be made of glass or plastic, and resemble miniature test tubes with tapered tips. They are mainly used in series test like the centrifuge of nucleic acid
50 ml Centrifuge Tubes,15 ml Centrifuge Tubes,5ml Centrifuge Tubes,Centrifuge Tube Holder,Micro centrifuge Tubes
Yong Yue Medical Technology(Kunshan) Co.,Ltd , https://www.yongyuepcr.com