After the grinding balls have been produced, a series of checks are carried out to ensure their quality. In the surface inspection of the grinding ball, the first is to check for the presence of sand and sand slag problems. And to clean the surface of the ball of sand and sand slag, so that the ball surface depression, leaving only the pure steel ball material.
Under normal circumstances, to ensure that the length of any one of the defects must not exceed one-tenth of the diameter of the grinding ball surface. And the distance between any two defects must exceed half the length of the smaller defect. Also make sure that the total length of all defects does not exceed a maximum of four tenths of the ball diameter. In a defective area, the thickness of the steel ball wall must not be less than ten millimeters of the actual wall thickness of the ball.
In the same way, we also need to check the grinding ball for the existence of air holes and air bubbles on the surface. Remember that all pores and bubble depths must be checked. In a defective area, the thickness of the steel ball wall should not be less than ten millimeters less than the actual wall thickness of the steel ball. The maximum allowable thickness of ten points is less than the minimum wall thickness of the steel ball.
Next, the inner surface of the steel ball is also ground to be inspected. The main contents include: The inner surface of the steel ball is mainly inspected with a mirror and must not show any cracks. Then the crack on the outer surface of the ball is also checked. It should be noted that the entire surface of the ball, including the core pouring holes, should be inspected or infiltrated.
In addition, records should be made on the preparation work, inspection process and inspection results of the quality inspection of grinding balls, and the quality test report on grinding balls should be carefully filled out. In the magnetic particle inspection, it is necessary to ensure that the field strength of sufficient magnetization should meet the relevant regulations, and the test equipment should be inspected in accordance with the relevant standards.