"S.G. IRON" derives its name from the form of the graphite. Its full title being "Spheroidal"Graphite cast iron". It is also know Ductile iron and nodular iron, S.G. Iron is a modern engineering material discovered in ferrous metallurgy in the last century. It was invented almost simultaneously, but independentily at Bicra Lab England and international lab at U.S.A. This casting is unique combination of carbon and silicon with very low percentage(Trace) sulpher in nodular shape than flake after metal treated with magnesium alloys. These casting have successfully replaced steel forging and malleable iron casting with proven techno commercial advantages.
The discontinuities which graphite flake creates in grey in grey iron are eliminated in Nodular Iron and the result and material has greatly improved properties including a high degree of toughness. Moreover, there is no limit to the size and nature of the casting. Nodular iron can sustain high loads without permanent deformation, Yet toleration bending and twisting without significant loss of strength. The strength and other mechanical properties of grey of grey iron tend to fall as section thickness increases but the rate of fall is much less in nodular iron in flake- graphite irons.
Why S.G.Iron
S.G. Iron has many engineering and commercial advantages like.
(1) Good castability having superior strength, weight ratio.
(2) Good machinability
(3) Good surface, hardenability, toughness, ductility, modulus of elasticity, fatugueresistant, wear resistant, can absorb thermal shock, corrosion-resistant, and can work in high temperature generated components impact load absorbing properties.
(4) Reduces component weight compared to steel forging with fooling cost, as economy in present competitive markets, thus more strength pre unit cost.
(5) Has highest endurance, strength and ductility.
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