Stainless steel precision casting has to undergo a series of post-treatments after the casting is completed. The post-treatment mainly deals with the surface quality and overall shape of the product. Its processes are the most complicated, including shot blasting, sandblasting, acid pickling, pickling, rough Grinding, fine grinding, shaping, welding repair, electropolishing, grinding, and other processes.
For products that require relatively high surface quality. To be sandblasted. Sandblasting is powered by compressed air, and sand is sprayed on the surface of the casting at a high speed through a spray gun to remove the residual sand and oxide scale remaining on the surface and inner hole of the casting.
In the post-treatment process, the product does not have a fixed process flow, and the process flow is usually coordinated according to the structure of the stainless steel precision casting product and the on-site work arrangement.
For example, during the cleaning process, there is no sequence of shot blasting, sandblasting, and rough grinding, which can be coordinated according to the site conditions.
As for products with thicker walls and complex structures, they are less prone to deformation. For some foreseeable deformations, measures such as cooling tooling and reasonable placement are generally taken during the wax pressing process to prevent them in order to reduce the deformation rate and repair rate.
Rough grinding is to use an emery cloth belt to grind the inner gate to a height of less than 1mm from the surface of the casting. Then fine grinding, according to the products with different surface quality requirements, choose the different thicknesses of emery cloth belt for fine grinding. It is necessary to concentrate on fine grinding to prevent the surface of the product from being scratched. The products that are transferred from the inspection workshop to the welding workshop are all products with surface defects.
Generally speaking, the surface defects of products can be divided into two categories: protrusions and depressions.
Protruding defects include flashing, burrs, steel beans, or more obvious parting lines.
Defects such as depressions include pores, shrinkage pits, cuts, abrasions, etc. Grinding and welding are the repair methods for the two major defects on the surface.
Grinding is mainly used pneumatic air guns, grinders, and other grinding tools to install different models and types of grinding heads. Smooth and smooth the protruding defects on the surface of the product. When repairing the protruding defects on the large surface of the product, you will choose a sanding head, which is faster.
There are clear requirements on the type, thickness, and blasting pressure of the sand used in the blasting process. Because excessive pressure can easily cause damage to the surface of the product, be careful not to place the casting directly against the nozzle of the spray gun during operation to prevent the casting from being damaged by a blowout. The surface of the product after sandblasting is much more delicate than the surface of the product after shot blasting.
But there are some holes, grooves, grooves, and other places where the sanding head cannot be repaired, and steel grinding heads are used. Because the steel grinding head is relatively thin, it is more convenient to repair those smaller places. Welding repair is a repair method for concave defects, such as pores, shrinkage pits, cuts, abrasions, etc.
The purpose of reshaping and welding is the same. It is to repair different types of defects in products through different methods to make unqualified products qualified. It is mainly aimed at the correction of shape-deformed products. Generally, products with simple shapes and thin wall thickness are easy to deform.