Method for removing defect of casting surface with spherical sand by sandblasting

Abstract

The invention discloses a method for removing defect of casting surface with spherical sand by sandblasting. Sandblasting is performed by using emergy as an abrasive in a conventional sandblasting method. Two abrasives used in the conventional method are easy to pulverize, so the production efficiency is low. The method of the invention comprises: a first step: selecting the spherical sand, wherein the particles of the spherical sand are required to be hard and round, chemical contents meet the sandblasting requirement, the sand aggregate has the advisable particle size of 16-30 meshes; and 5-15% by weight of irregular shaped sand aggregate is added to the spherical sand and used as a cutting abrasive; a second step: drying the spherical sand to less than 2% of water content; a third step: removing soil and other impurities in the spherical sand; a fourth step: selecting a sandblasting pressure according to the casting size and thickness, controlling the pressure at 0.55-0.6 MPa, packing the spherical sand into a sandblasting bucket, sucking the sand into a sandblasting pipe by compressed air generated by an air compressor, sandblasting the surface through a secondary inlet type gun head, then subjecting the casting to fluorescence detection after sandblasting. The method is used for sandblasting.

Description

Technical field: [0001] The invention relates to a sand blasting method in the foundry industry, in particular to a method for removing surface defects of castings by blasting spherical sand. Background technique: [0002] There are two traditional sandblasting methods, one uses river sand as the abrasive for sandblasting, and the other uses corundum sand as the abrasive for sandblasting. The two abrasives are easy to pulverize and the production efficiency is not high. The production environment is dusty, the operators are prone to occupational diseases, and it is easy to introduce the illusion of unsuitable fluorescence inspection, which greatly increases the possibility of misjudgment in the judgment of casting product quality, especially for precision castings with high requirements. The secondary and multiple costs of casting repair and inspection are greatly improved. [0003] River sand blasting cannot completely remove the microscopic residual shell attached to the ...

AI Technical Summary

Problems solved by technology

[0002] There are two traditional sandblasting methods, one uses river sand as the abrasive for sandblasting, and the other uses corundum sand as the abrasive for sandblasting. The two abrasives are easy to pulverize and the production efficiency is not high. The production environment is dusty, the operators are prone to occupational diseases, and it is easy to introduce the illusion of unsuitable fluorescence inspection, which greatly increases the possibility of misjudgment in the judgment of casting product quality, especially for precision castings with high requirements. The secondary and multiple costs of casting repair and inspection are greatly increased

[0003] Sand blasting with river sand cannot completely remove the microscopic residual shell attached to the surface of the casting, so that the penetrating liquid invades into the residual sand powder during the fluorescence detection, and it is easy to cause the illusion of fluorescence defects during the development process

The pulverization of river sand is very serious during the sandblasting process, and it is easy to cause dust to accumulate in some scratches or micro-porosity on the surface of the casting, polluting the penetrant and developer, making the test results inaccurate, and making the defects that do not exist in the original Occurs on fluorescence detection, often manifested as star-shaped fluorescent defects

[0004] Compared with river sand, corundum sand has a lower pulverization rate, but generally speaking, it still causes serious dust pollution in the operating environment of workers, and the comprehensive sandblasting efficiency is not high, and the price is high, so it is not widely used in actual production

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