S.G. (Spheroidal Graphite) Iron is a ductile Iron. It is typically used for Engineering applications where brittle metals are not appropriate. For details on SGI, start with a web search or consult a material handbook.
There are a variety of 'Spheroidal or Nodular Graphite Irons' in UK and in Commonwealth Countries while in US these are known as 'Ductile Irons'. These are basically in casting forms.
British Standard Specification for "Iron Castings with Spheroidal or Nodular Graphite -BS. 2789.1961. Their grades are -
If you do refer to this specification, will be able to get the physical properties there.
SNG 24/17 these with a ferritic matrix, in which resistance to impact is of paramount importance.
SNG 27/12 Those with a mainly ferritic matrix, of moderately high tensile strength in which high ductility and toughness are of great importance.
SNG 32/7 Those with a ferritic-pearlitic matrix, combining strength with reasonable ductility and forming an intermediate grade.
SNG 32/2, SNG 42/2, SNG 47/2 Those with a mainly pearlitic matrix, characterised by high tensile strength, but in which ductility and resistance to impact are less importance.
Pearlitic irons with spheroidal or nodular graphite covered by grades SNG 32/7, SNG 37/2, SNG 42/2, and SNG 42/7 will respond to most forms of heat treatment including quenching and tempering, induction or flame hardening and normalising.
All grades of irons in this specification are suitable for pressure purposes at temperatures up to 650º F (343º C).
SG Iron Castings
Re: SG Iron Castings
