Knowledge

Section 1: Advantages for Large Cast Steel Parts

The application of zircon sand in large cast steel parts has significant advantages, mainly reflected in the following aspects: ​​​​​​​

 

I. Improving the Surface Quality and Yield of Castings

Preventing Metal Penetration and Sand Adhesion: The unique spherical particle shape and excellent permeability of Baozhu sand make it effective in preventing metal penetration and sand adhesion on the thick surfaces, hot spots, and riser roots of large steel castings, thereby enhancing the surface quality of the castings.

Reducing Casting Defects: Baozhu sand has a low thermal expansion rate, which can prevent casting expansion defects. Additionally, its good fluidity and filling properties result in high dimensional accuracy of the castings, fewer cracks and surface defects, thus increasing the yield of the castings.

 

II. Reducing Production Costs and Cleaning Workload

Reducing sand usage: The bulk density of Baozhu sand is relatively low. Compared with chromite sand and zircon sand, the weight of sand used in making the same model (core) is significantly reduced, thereby lowering production costs.

Reducing cleaning workload: The spherical particle shape of Baozhu sand makes it easy to fill complex-shaped casting parts, reducing the occurrence of sand sticking defects and lowering the workload for cleaning and finishing.

 

III. Good Regeneration and Environmental Friendliness

Good Regeneration: The regeneration of zircon sand is excellent, allowing for repeated reuse with minimal breakage. This further reduces the waste sand discharge during the casting production process and lowers material consumption.

Environmental Advantages: As a green and environmentally friendly casting sand, zircon sand generates little or no dust and has a low content of silicon dust, posing no risk of silicosis. This enables the casting production process using zircon sand to improve the production environment and reduce health risks to workers. Additionally, the recycling of zircon sand aligns with the requirements of sustainable development and offers significant environmental benefits.

 

IV. Wide Application Range

Applicable to various casting processes: Baozhu sand is widely used in various casting processes such as resin sand (furan resin, phenolic resin), sodium silicate sand (CO₂ hardening), coated sand, etc.

Applicable to various metal materials: Baozhu sand can be used to produce various metal castings, such as carbon steel, alloy steel (high manganese steel, high chromium cast iron), cast iron, cast copper, etc.

 

V. Advantages in Specific Casting Processes

Furan Resin Sand Molding and Core Making: When furan resin is used as the binder for Baozhu sand, its hardening speed is faster than that of silica sand. Moreover, with the same amount of resin added, the strength is significantly increased. Particularly, the tensile strength after 24 hours is more than 50% higher than that of silica sand. Using Baozhu sand not only reduces the amount of resin added, lowers costs, and improves production efficiency, but also greatly reduces the probability of defects such as gas holes in castings.

Lost Foam Casting: In lost foam casting, when Baozhu sand is used as the molding material, the amount of resin can be reduced by one-third, further lowering production costs.

 

Section 2: Case Studies of Large Cast Steel Parts

 

Case 1: Technological Transformation of a Large Valve Cast Steel Factory

A certain valve cast steel factory originally used alkaline phenolic resin coated sand as facing sand and sodium silicate sand as backing sand. This process had some problems, such as a strong odor during pouring with alkaline phenolic resin coated sand, inability to fully recycle old sand, and a reuse rate of only 50% for sodium silicate backing sand, resulting in severe over-standard discharge of waste sand from the factory.

Application of Baozhu Sand and Bonny Resin Process: A combination process of Baozhu sand and Bonny resin. Specific parameters are as follows:

- Baozhu sand: 40/100 mesh (five-sieve system distribution)

- Bonny resin addition: Generally 0.7% to 0.8%

- Curing agent addition: 30% to 40% (of the resin)

- Appropriate coatings are used in conjunction

Effects:

Continuous and stable production, with significant improvement in casting quality. At the same time, only 30 to 50 kg of Baozhu sand is consumed per ton of castings, achieving a double harvest of economic and environmental benefits.

 

Case 2:Lost Foam Casting of Large High Manganese Steel Castings

When a certain company was using the lost foam process to produce high manganese steel castings, it faced serious problems of sand sticking and sand inclusion. These issues not only increased the workload of surface cleaning and grinding of the castings, raised production costs, but also affected the surface quality of the castings.

By using zircon sand as the molding material, the spherical particle shape and good permeability of zircon sand effectively prevented and reduced casting defects such as slag inclusion and porosity.

After using zircon sand, the company has completely eliminated casting defects such as sand sticking and sand inclusion, and saved nearly 6% of production costs.

 

Case 3: Water Jacket for Large Diesel Engine

When a certain company was manufacturing water jackets for diesel engines, the original sand used had disadvantages such as a large expansion coefficient, a large amount of binder added, and a large amount of gas generated, which affected the product yield.

By using zircon sand to make water jackets for diesel engines, the characteristics of the original sand were maintained while overcoming its shortcomings.

After using zircon sand, the factory reduced the amount of resin added and increased the product yield.

 

Vigor has more than 18 years experience on castings. If you have any question and demand of products development or improve your supply chain, please feel free to contact us at info@castings-forging.com