Grey Cast Iron Casting

The name grey iron is because of the gray color of the fracture it forms, which
is due to the presence of graphite. Grey iron die casting is the most common
and widely used casting material.

Grey iron is so popular in engineering applications because of its relatively
low cost and the properties it presented. The grey iron has good galling and
wears resistance because the graphite flakes self lubricates, and it also gives
the gray iron part an excellent damping capacity because it absorbs the energy
and converts it into heat.

Grey iron is very suitable for casting works. But during the casting process, a
less solidification shrinkage than other casting iron shall be considered. The
silicon promotes good corrosion resistance and increased fluidity when casting.

Below is a reference chart of other ASTM standards affecting grey iron.

ASTM A395 & ASME SA395: ferritic ductile iron pressure-retaining castings for

use at elevated temperatures

ASTM A439: austenitic ductile iron castings

ASTM A476 & ASME SA476: ductile iron castings for paper mill dryer rolls

ASTM A536 & SAE J434: ductile iron castings

ASTM A571 & ASME SA571: austenitic ductile iron castings for pressure-
containing parts suitable for low-temperature service

ASTM A874: ferritic ductile iron castings suitable for low-temperature service

ASTM A897: austempered ductile iron castings

Ductile iron

Description of Gray Cast Iron
Gray cast iron is a type of cast iron. Carbon is present in cast iron in the
form of flake graphite. The fracture is gray in color. It has good casting and
cutting properties and good wear resistance. Gray cast iron is used in the
manufacture of frames, boxes, etc. The graphite of gray cast iron is in the
form of flake. The effective bearing area is relatively small, and the graphite
tip is easy to produce stress concentration, so the strength, plasticity, and
toughness of gray cast iron are lower than other cast iron. However, it has
excellent vibration damping, low notch sensitivity, and high wear resistance.



Introduction to Cast Iron Molding
Cast iron moldings are broadly defined as objects cast in iron, which is the
most commonly used metal.

Numerical simulation of the solidification process of thick and large section
ductile iron castings with the application of computer was carried out for the
temperature field. Increasing the strength of the mold shell, baking
temperature and decreasing the pouring temperature are beneficial to reduce the
scrap rate of castings and improve the quality of ductile iron castings.

Factors Affecting the Performance of Gray Cast Iron
The influence of chemical composition

In production, the quality fraction of carbon and silicon is mainly controlled.
If the mass fraction of carbon and silicon is too low, the cast iron is easy to
appear white mouth organization, and the mechanical properties and casting
performance are very low; if the mass fraction of carbon and silicon is too
high, the graphite flakes are too much and coarse, and even the graphite floats
on the surface of the iron, which reduces the performance and quality of the
castings. Therefore, the carbon and silicon content of gray cast iron is
generally controlled at 2% to 4% C; 1.0% to 2.0% Si; 0.5% to 1.4% Mn.

The effect of cooling rate

Under certain casting process conditions, the cooling rate of the casting has a
great impact on the degree of graphitization. Castings of different wall
thickness with the increase in wall thickness, the cooling rate slows down, and
carbon atoms have sufficient diffusion time. It is conducive to the full
graphitization process, room temperature organization is easy to form gray iron
organization; but thin-walled parts in the cooling process, the cooling rate is
too fast, easy to form a white mouth iron organization.

Rayforce Manufacture as one of the most professional cast iron casting
manufacturers and metal casting companies, we provide metal casting china, cast
iron and ductile iron, cast iron ductile iron and etc. Want to know iron
casting price per kg or more? Please contact us.

Minimum Order: 3000 metric tons

Click to Enlarge