Metal Castings in China
Nowadays, the outputs of all kinds of
metal castings reach to more than 5 million tons in China, these
metal castings widely used in every field of national economy,
according to the statistics, the metal castings occupied 30-85% of
the whole machine weight in machine equipments. At the same time,
because the materials, technology and detective methods improve
fast, the inner quality of castings, size accuracy and the surface
finish reach to a high level, so among the machine products, the
work of metal casting design is very large.
Metal castings produced depend on the casting methods.
1. The metal casting methods of machine tool castings can produce
any kind of blanks and parts with complex shapes, such as the bodies
of the internal-combustion engines, air cylinders, screw propellers
and all kinds of pumps and so on. Because the limit of casting
methods to the metal castings is small, so the metal castings can
use reasonable section shapes base on the situation of force.
2. Use special casting, inlay casting and double-metal metal casting
can make the structures of parts more reasonable and these methods
can solve some problems which other metal casting methods can not
solve, so they can acquire more economic effects. To some small and
complex parts, we can use melted module precise casting and ceramic
core methods to produce; they not only solve process problems but
also increase the passing rate and save the materials.
3. The some iron parts only can be produced by casting methods.
The characteristics of the metal castings
General speaking, the cost of metal castings is low because the row
materials are low and can be get easily, besides, some wasting
metals can be melted again, the cost of the equipments of metal
casting is low and so on.
The problems of metal castings produced in casting methods.
The mechanical properties of metal castings is not better than
forgings which both have the same metal materials, the quality of
metal castings is not stable and easily produce flaw products, so we
do not use these metal castings to make some important parts.
In short, in order to produce good metals castings, we not only need
to know about the methods of casting, but also need to consider what
metal castings we desire.