Influence of steel shot of different particle size and hardness on different processes

　　Steel shot in different particle size and hardness products are used in different processes, such as surface strengthening, etc. Coating of workpieces, sandblasting before workpiece bonding can remove all dirt such as rust on the surface of workpieces, and establish a very important basic pattern (usually so-called rough surface) on the surface of workpieces, and can be replaced by different Abrasives with different particle sizes can achieve different degrees of roughness, which greatly improves the bonding force between workpieces and coatings and plating materials. Steel shot is used for pretreatment of steel plate, generally used for rust removal before painting

　　The larger the particle size of the steel shot, the higher the projection speed, the higher the surface roughness value; the larger the shot blasting amount, the higher the cleaning efficiency; the graded steel shot has higher cleaning efficiency than the single-size steel shot of the same nominal size. A lower surface roughness value can be obtained; the surface roughness has a greater impact on the coating performance. The higher the surface roughness value, the worse the corrosion resistance, but in the case of rough surface, different surface roughness values have little effect on the adhesion of the paint.

　　The standard for selecting steel shot mainly depends on the workpiece you want to clean. For non-ferrous metals, aluminum shot or stainless steel shot is generally used. Steel shot is used for ordinary steel weldments, castings, steel, etc. The hardness of glass shot is lower than that of the first two shots, and it is mainly used in stainless steel, titanium, aluminum, magnesium and other situations where iron pollution is not allowed. It can also be used for the second treatment after steel shot peening to remove iron pollution and reduce the surface roughness of parts.

　　Although many factors affect the casting surface roughness, shot blasting is the last process that affects the casting surface. Shot blasting can change the original surface of the casting. By choosing the appropriate steel shot size, projection speed and cleaning process, a higher casting surface can be obtained at a very low cost. In the process of casting cleaning, the essence of cleaning is to remove the sticky sand and oxide skin on the surface of the casting and expose the wood body of the casting. Although prolonging the cleaning time can change the surface of the casting and the roughness value, this method is not enough to clean the casting. Appropriate, at least uneconomical.