How to select iron casting process

The most common iron casting process is sand casting, followed by special casting methods, such as metal mold casting, investment casting, plaster casting and so on. The sand casting process can be divided into green sand, organic binder of sand, resin sand and lost foam etc.

Casting selecting principle:

First, give priority to using sand casting

According to statistics, sand casting has taken about 60% to 70% of the total casting production, and about 70% of which is green sand casting.

Mainly due to low cost of sand casting than other casting methods, its production process is simple, and has short production cycle. So as the car engine cylinder block, cylinder head, crankshaft, etc. are produced by green sand casting process.

When the green sand can not meet the requirements and then you could consider the use of dry sand or other sand. The weight range of green sand casting is from several kilograms to hundreds of kilograms, while the production of dry clay casting can weigh several tons.

In general, for medium and large iron castings, you choose self-hardening resin sand. As for steel castings, you could choose the water glass sand. This can get accurate dimensions, smooth surface of the castings, but the cost is higher.

Of course, as for the sand castings, the accuracy, surface finish, material density and microstructure, mechanical properties are very general, not very high, so when castings have these higher performance requirements, you should use other casting methods, such as investment casting (lost wax) casting, die casting, low pressure casting and so on.

Second, the casting process should be suited to annual demand

As for sand casting process, for large volume production, you could choose the automatic molding line. Old-fashioned shock or shock-type compression molding machine production line productivity is not high enough, workers in labor-intensive, noisy and does not meet the requirements of mass production.

For medium-sized castings, they are usually too large for automatic molding line, so you can choose high-pressure molding machine.

For large-sized castings, you could choose resin sand molding process, which could get better quality.

As for the small batch production of heavy castings, hand-shape is still an important way to adapt to a variety of complex shapes.

Low pressure die casting, die casting, centrifugal casting and other casting methods, because of equipment and tooling is expensive, so only suitable for mass production.

Third, considering the production cost and dimensional requirements

Various casting processes have different dimension precision, and different initial investment and productivity, therefore, the economic benefits are also differences. So you should consider all its aspects to determine the high economic benefits and the high casting requirements, but ensure that the casting process is applicable.