Method for Clearing Dead Corner in Dalian Shot Blasting Processing

The processing time of Dalian shot blasting depends on the shot blasting effect generated by the workpiece during the shot blasting process, and the principle is to achieve the required shot blasting strength. (Usually around 30 minutes). Additionally, it should be noted that shot peening strength is now mostly measured using Almen's arc height gauge as described in the American SAE standard J442. Almen arc height gauge is a 70 gauge carbon steel with a thickness of 0.8, 1.3, or 2.4mm standard dimensions, with a hardness of HRC44-50. The sample is fixed on a special fixture, and one side is shot blasted. Then, the arc height of the bent steel bar sample is measured using an arc height gauge to obtain the shot blasting strength.

The principle of shot blasting is to use an electric motor to drive the impeller body to rotate (directly driven or driven by a V-belt), and by the action of centrifugal force, shot with a diameter of about 0.2-3.0 (including cast steel shot, steel wire cut shot, stainless steel shot, and other different types) is thrown onto the surface of the workpiece to achieve a certain roughness, making the workpiece beautiful, or changing the welding tensile stress to compressive stress, improving the service life of the workpiece. By improving the surface roughness of the workpiece, the adhesion of the paint film for subsequent painting of the workpiece is also improved. Its meaning is that shot blasting can be the preceding process of the painting process.

Method for Clearing Dead Corner in Dalian Shot Blasting Processing

The main method is to perform a secondary supplementary blasting operation after shot blasting. One is to use a sandblasting machine for manual sandblasting and repair cleaning, the other is to use a steel brush for cleaning, and the third is to have a polishing machine for processing. Of course, if the requirements for processing some grooves are not very high, there is no need for secondary cleaning.

Only within a reasonable range can the hardness of steel shot and sand have good impact performance. If the hardness of steel shot and sand is too high, its brittleness is relatively high and it is easy to break; If the hardness of steel shot and sand is too low, its impact effect is poor, and the shot blasting time and other costs increase in disguised form. So steel shot and sand can only truly save production costs within an appropriate hardness range.

Due to the significant relationship between the properties of steel shot and cleaning efficiency, surface roughness, and cleaning cost, the various indicators of A, B, and C steel shot are analyzed. The results show that in terms of particle size distribution, C steel shot is slightly larger, B steel shot is slightly larger, and only A steel shot has a particle size distribution that meets the national standard. In terms of hardness distribution, the required hardness for cleaning castings is HRC40-50. The hardness of B and C steel shot exceeds HRC50, and only A steel shot meets the requirements with a very small difference, only HRC5.8.