The process of cleaning precision castings from molds, removing excess parts outside the main body, and polishing the inner and outer surfaces of the castings.

Core removal and surface cleaning:

Divided into two categories: dry method and wet method. Dry cleaning is the use of mechanical equipment to clean castings, which has the advantages of simple equipment, high production efficiency, great adaptability to different types of castings, and the ability to remove the core and effectively clean the surface. However, the disadvantage is that the equipment generally causes dust flying, high noise, and environmental pollution during operation. Wet cleaning does not produce dust, but due to the use of water as a medium, the surface of castings is prone to rust and dirt. During the workflow, a large amount of sewage and cement sand are generated, resulting in problems such as the regeneration of sand and water and sludge treatment.

The commonly used dry and wet cleaning methods in production are:

1. Drum cleaning. Put the casting and star iron together into a circular drum. When the drum rotates, the sand inside and outside the casting will be removed due to the collision and friction between the casting, star iron, and waste sand. Polishing the surface of castings can also partially remove burrs and burrs. This type of equipment can be used to clean small and medium-sized castings with simpler shapes and thicker walls.

2. Shot blasting cleaning. The impact force of high-speed steel shot, iron shot, and abrasive flow is used to clean the core, sand sticking, and polish the surface of castings. In addition, common shot blasting cleaning equipment also includes shot blasting cleaning tables and rooms. Shot blasting cleaning machines used for continuous production include chain plate shot blasting drums, continuous shot blasting cleaning tables, and suspended continuous production shot blasting cleaning rooms, which have high operating and maintenance costs.

3. Hydraulic sand cleaning. Inject high-pressure water from the nozzle to the disposed casting through the pipeline, and use the kinetic energy and scouring effect of the water flow to clean the core and sand sticking of the casting. Hydraulic sand cleaning is generally equipped with an open cleaning room composed of steel and steel plates, with a rotating workbench at the bottom. The nozzle is installed on the side wall, which can move up and down and rotate, allowing high-pressure water flow to be directed to any part except the bottom of the casting, Sometimes, in order to improve the efficiency of cleaning the surface of precision castings with sand sticking, abrasive materials such as quartz sand are introduced into the appropriate position of the spray gun to achieve high-speed water sand flow. This method is generally called water sand cleaning.

4. Water blasting for sand removal. After pouring the mold, when the precision casting cools to the specified temperature, the box is opened and immediately immersed in a water pool. Water seeps into the mold through all gaps and rapidly vaporizes and explodes in contact with high-temperature metals. The shock wave can basically clean the sand attached to the inside and outside of the casting. The water explosion sand cleaning method has the advantages of short working time and high efficiency, and is widely used in domestic steel casting workshops, Generally used for the disposal of steel castings with a carbon content below 0.35% and a relatively simple appearance.