The occurrence of defects will harm the screw's convent […]
The occurrence of defects will harm the screw's conventional use of life, and affect the safety of the processing process. Now, Onyx anti-wear maintenance system specially designed for plasticizing screw has been developed, which can prevent the screw from wear and has high impact resistance.
In order to achieve an economically viable life cycle, plasticizing screw with carbon metal coating is very important when processing high additive level professional composite materials. The carbon based coating ensures the necessary high wear resistance, while the steel under the coating is subjected to mechanical loading and, with excellent strength characteristics, ensures high safety under impact stress.
In coatings, defects such as pinholes, cracks and nonmetallic impurities (such as oxides or slurries) are important factors leading to metal fatigue. The wear mechanism of these defect areas is closely related to the long working life, so it is necessary to optimize the manufacturing process to prevent the occurrence of defects as much as possible, or at least to minimize the possibility of their occurrence. Through the development of a new Engel anti-wear maintenance system for plasticizing screw, this plan was successfully completed.
Screws are produced using straight and non distorted bar data. The initial generalization of the screw is obtained by milling or rotary cutting, and the internal stress of the data is released when most of the data are removed. Metal requirements through repeated annealing and remodeling, and then to produce stress-free screw semi-finished products. Then, the carbide powder is heated to about 1200 ℃ in the burner and accelerated to sonic speed or above (300m / S ~ 2000m / s). At this speed, the semi fluid particles hit the rough surface of the screw semi-finished product and adhere to the untreated workpiece. The satisfied particle velocity can also ensure that there is hardly any pinhole on the surface even at the edge of the screw with unstable view point. Hot powder particles rapidly cool from 1200 ℃ to about 150 ℃, resulting in volume reduction will lead to surface tension. Then, the tension is offset by the high-speed motion energy of particles, because the impact of particles will lead to surface plastic deformation and constitute kneading strength. Under 30 ~ 60 impacts, a uniform coating will occur on the whole surface.
After that, the coating is annealed in inert gas or vacuum furnace. By heating the substrate, the microstructure changes from hollow cubic iron to hollow cubic austenite, and the change of microstructure will not affect the coating. During this period, the alloy elements contained in the coating, which is in the state of extreme thermodynamic imbalance, will occur dispersion compensation. The coating on the edge of the substrate also changes significantly, and then improves adhesion. After the heating period, the steel is cooled through several stages. The cooling rate has great influence on the change of microstructure and the function of screw substrate. Depending on the process at that time, the multi-stage cooling process with different cooling rates prevents the corresponding error source, optimizes the function of layer and substrate, and ensures that the produced screw is crack free and almost free from distortion. The required fineness of the screw means that the required fineness of the screw is required. Depending on the basic steel used for the screw, subsequent annealing and rough grinding at 400 ℃ to 650 ℃ can obtain the desired steel function. After annealing and rough grinding, the screw is machined to obtain the surface roughness required in the plasticizing unit.
The characteristic of this new system is its improved durability, which is proved by the results of drop weight impact test. Compared with other coating systems, the maximum impact force that can be accepted by the coating system is 300% higher before the initial cracking.