The main factors that affect the wear of shot blasting machine parts are parts materials, working load, movement speed, temperature, humidity, environment, lubrication, surface processing quality, assembly and installation quality, structural characteristics and movement properties of the parts.
1. The impact of shot blasting machine parts materials on wear
The wear resistance of shot blasting machine parts mainly depends on its hardness and toughness. The hardness determines the ability of the surface to resist deformation, but too high hardness will easily increase the brittleness and cause abrasive flaking on the surface of the accessories; toughness can prevent the generation of abrasive particles and improve its wear resistance.
After heat treatment or chemical heat treatment, the parts can obtain excellent mechanical properties and improve the wear resistance of the parts. Sometimes, surface flame quenching or high-frequency quenching can be used to improve the wear resistance of the material, or the method of carburizing, nitriding, and carbonitriding can be used to make the surface of the steel have higher hardness and wear resistance.
In the combined parts, such as the shaft in the bearing pair, since it is the main part that needs to be processed, it should be made of wear-resistant materials; for simpler parts, such as bearing bushes or bushes, babbitt alloys should be used , Copper-based alloys, lead-based or aluminum-based alloys and other softer materials (also called anti-friction alloys) to achieve the purpose of reducing friction and improving wear resistance.
2. The impact of working load of shot blasting machine parts on wear
Under normal circumstances, the greater the unit pressure, the more severe the wear of the parts. In addition to the size of the load, the load characteristics also have a direct impact on wear, such as static load or variable load, whether there is an impact load, whether it is a short-term load or a long-term load, and so on. Under normal circumstances, the machine parts should not be overloaded and subjected to shock loads for a long time.
3. The influence of the movement speed of shot blasting machine parts on wear
When the machine is running, the speed, direction, variable speed and uniform speed, forward and reverse rotation, open and stop at all times, all have varying degrees of influence on wear. Generally, under dry friction conditions, the higher the speed, the faster the wear; when there is lubricating oil, the higher the speed, the easier it is to form liquid friction and reduce wear; the higher the starting frequency of the machine, the faster the wear of the parts。
4. The influence of temperature, humidity and environment on wear
Temperature mainly affects the lubricating oil adsorption strength. The lubricating oil film has quite high mechanical stability, but the temperature and chemical stability are relatively poor. When there is a high temperature and chemical changes, the lubricating oil will lose its adsorption performance.
If the working environment of the machine parts is affected by humidity, water vapor, gas, dust, iron filings or other liquid or gas chemical corrosive media, it will cause and accelerate the oxidation and corrosion of the machine parts.
5. The influence of lubrication on the wear of shot blasting machine parts
Lubrication plays an important role in reducing the wear of mechanical parts. For example, the liquid lubrication state can prevent adhesive wear; the supply of clean lubricating oil to the friction pair can prevent abrasive wear; the correct selection of lubricating materials can reduce corrosion wear and fatigue wear. Keeping enough lubricant in the lubricated friction pair of the machine parts can reduce the direct friction between the metal of the friction pair, reduce power consumption, extend the service life of the parts, and ensure the normal operation of the equipment. Lubrication can effectively improve the effects of wear and is of great significance to mechanical maintenance.
6. The influence of surface processing quality of shot blasting machine parts on wear
Surface processing quality mainly refers to mechanical processing quality, including macroscopic geometry, surface roughness and direction of tool marks.
(1) The effect of macroscopic geometry on wear. The so-called macroscopic geometry refers to the deviation of the actual shape from the ideal shape after processing, that is, the processing accuracy, such as roundness, cylindricity, parallelism, and perpendicularity. The deviation of the macroscopic geometry makes The uneven load distribution on the surface of the parts can easily cause severe local wear.
(2) The effect of surface roughness on wear is not that the smaller the surface roughness value, the smaller the wear. According to the test, there is a reasonable surface roughness under each load to make the wear less; under the same load, usually the smaller the surface roughness value, the smaller the abrasion, but after the reasonable point is exceeded, the abrasion will be Gradually rise. This is because the surface is too smooth, so that the contact surface increases, and the intermolecular attraction is enhanced, so the possibility of adhesive wear increases.
(3) The influence of tool mark direction on wear The tool mark direction has a greater influence on wear. If the tool mark directions of the two friction surfaces are parallel and consistent with the direction of movement, the wear is small. If the direction of the knife marks on the two friction surfaces is parallel but perpendicular to the direction of movement, the wear will be greater. If the direction of the tool mark crosses the direction of movement, the wear is between the two.