What cast iron has modular or spheroidal graphite?
Ductile iron
Ductile iron, also known as ductile cast iron, nodular cast iron, spheroidal graphite iron, spheroidal graphite cast iron and SG iron, is a type of graphite-rich cast iron discovered in 1943 by Keith Millis.
Table of Contents
How many grades of cast iron are there?

four cast iron types
We’ll give a brief overview on the four cast iron types, which are gray, white, malleable, and ductile.
What are the types of graphite cast iron?
(1) both C-type and F-type graphite are primary graphite, and graphite is precipitated from molten iron under hypereutectic composition. The characteristics of C-type graphite are long, thick and straight. F-type graphite only appears in castings as thin as single casting piston rings.
What is spheroidal cast iron used for?
Spheroidal graphite (SG) cast iron has excellent toughness; it has higher elongation and is used widely, for example, in crankshafts. Unlike malleable iron, nodular iron is produced directly from the melt and does not require heat treatment. Magnesium or cerium is added to the ladle just before casting.

What is spheroidal form?
A spheroid, also known as an ellipsoid of revolution or rotational ellipsoid, is a quadric surface obtained by rotating an ellipse about one of its principal axes; in other words, an ellipsoid with two equal semi-diameters. A spheroid has circular symmetry.
What are the 4 types of cast iron?
The 4 Types of Cast Iron
- Grey Cast Iron.
- White Cast Iron.
- Ductile Cast Iron.
- Malleable Cast Iron.
How is spheroidal graphite iron made?
Nodular (spheroidal graphite) cast iron The formation of nodules or spheroids occurs when eutectic graphite separates from the molten iron during solidification.
What is the properties of spheroidal cast iron?
Spheroidal cast iron is a further development of grey cast iron (EN-GJL). Due to the high carbon content, grey cast iron has significantly better and more efficient casting properties than steel. On the other hand, and as a result of that, grey cast iron is very brittle and not weldable.
How is spheroidal graphite cast iron is designated in Indian Standard explain with suitable example?
(f) Nodular or spheroidal graphite cast iron. According to Indian standard specifications, the nodular or spheroidal graphite cast iron is designated by the alphabets ‘SG’ followed by the figures indicating the minimum tensile strength in MPa or N/mm2 and the percentage elongation.
What does SG iron stand for?
Spheroidal Graphite Iron
SG Iron is also known as Ductile Cast Iron, Nodular Cast Iron, Spheroidal Graphite Iron and Spherulitic Cast Iron. This grade of Iron was developed over 60 years ago and in the USA. As the name Ductile Iron suggests this grade of Cast Iron has a degree of ductility.
What is the meaning of cast iron SG 400 15?
According to Indian standard specifications, SG 400/15 means Spheroidal graphite cast iron with minimum tensile strength 400 MPa and 15 percent elongation.