How to produce large iron castings
In China, there are many
iron foundries, who
mainly produced large iron
castings, such as for the
ship parts, drying cylinders, machine bases and so on. Therefore,
there are many different
casting processes for producing large
cast iron parts. Herein,
we mainly introduced some normal casting methods for them.
1. Resin sand casting process
Resin sand casting process is very common
casting method to produce
middle size iron castings, unit weight from dozens kilograms to
Several tons. Resin sand
castings have good surface quality and dimension tolerances,
and less of casting defects, so this process is usually used for
producing complex iron castings with high requirements.
Moreover, this process could use wooden or
resin patterns, so can
reduce the costs for patterns. This is useful to small annual demand
2. Lost foam casting
Lost foam casting process have better surface quality than resin
sand casting process, and it also can reduce the manpower for
could reduce the molding costs for workers. In China, labors have
become more and more expensive, so this process will be a direction
of development to casting process for large iron and
Moreover, lost foam molding process could produce larger
metal castings than resin
However, this process can emit pollution air, and have to use
to produce the foam molds, so the high pattern costs will restrict
the choice of clients.
3. Buried foundry
As for the very large iron castings, such as dozens of tons weight
castings, the buried foundry will be the best choice.
process normally uses dry clay sand as the molding material, and put
the clay sand into the deep hole, then after molding, pour the
liquid iron into the hole.
Of course, this process will have more casting process and worse
surface quality than other processes, however, you could repair the
defects, and use machining to keep the tolerance for the key
This process is widely used for producing super large iron castings,
but normally these foundries will not produce small castings. Their
casting and machining workshops are specifically producing
large iron castings.
As for producing large iron castings,
the iron foundries should have rich experiences and suitable casting
process. Lacking either of them will cause the failure and loss.