With the continuous development of casting technology and the use of high-precision marine casting molds, the precision level of sand casting has been greatly improved. Therefore, sand casting is still a widely used casting method in the world. However, compared with investment casting, investment casting has higher casting accuracy, smaller machining allowance and better surface roughness. Investment casting is suitable for the production of high-precision small and medium-sized castings. The applicability is relatively small and the cost is higher than that of sand casting. Therefore, the casting method of marine castings should be selected according to the actual requirements of castings.

Factors affecting dimensional accuracy of marine die castings

1) Die casting die structure, manufacturing error and installation error;

2) Shrinkage error of die casting alloy;

3) Errors caused by different positions of die casting parts in the mold; 4) Structure, surface cleaning and finishing of die casting parts and 4) dimensional changes caused by finishing;

5) Errors caused by thermal expansion during the working process and wear during the use of the die-casting die;

6) Errors caused by changes in die casting process parameters (alloy temperature, mold temperature, pouring temperature, injection speed, injection specific pressure, etc.).

For example, sand casting is generally low-cost and has no special constraints on product structure, complexity, casting material and weight. It is a general casting method.