Stainless Steel Precision Casting: Specific Requirements for Foundry Sand_Jiangxi Ruiguan Precision Casting Co., Ltd. | Stainless Steel Electronic Hardware | Lock Casting

Stainless Steel Precision Casting: Specific Requirements for Foundry Sand

Date：

2022-06-24

The particle shape and particle composition of foundry sand have an impact on the fluidity, compactness, air permeability, strength and permeability of liquid metal of the foundry sand, and are important indicators of the quality of the foundry sand.

Stainless Steel Precision Casting: Specific Requirements for Foundry Sand

In stainless steel precision casting, the foundry sand should meet the following requirements:

1. High purity and cleanliness. Taking silica sand as an example, the sand for cast iron requires a SiO2 content of more than 90%, and the larger steel casting requires a SiO2 content of more than 97%;

2. High refractoriness and thermal stability;

3. Appropriate particle shape and particle composition;

4. It is not easy to be wetted by liquid metal;

5. Cheap and easy to get.

Particle shape and composition

Particle shape: There are generally three shapes of foundry sand. 1. Round sand: The particles are round or close to round, with a smooth surface and no prominent edges and corners. 2. Polygonal sand: The particles are polygonal and mostly obtuse. 3. Sharp-angled sand: The particles are sharp-angled, and most of them are acute-angled. The particle shape of foundry sand is generally expressed by the angle coefficient (the actual specific surface area of the sand/the theoretical specific surface area of the sand).

Particle composition: The particle composition of sand is represented by the sieve number. The method of determination is to pour the dry sand after washing with water to remove the mud and drying it into a standard sieve, and then put it on a sand sieving machine for sieving. The sand remaining on the sieve is weighed separately, and the particle composition is usually indicated by the head and tail sieve numbers of the three adjacent sieves in which the sand particles are concentrated after standard sieve sieving.