More info
Description / Abstract:
This material specification covers castings made of high
temperature resistant iron as used in automotive and allied
industries, including the mechanical properties from separately
cast Y-block test samples and compositional requirements in the
product castings. Any specific requirements for the whole or a
critical section of a casting shall be identified on the
engineering drawing.
Material Description. Grades of nodular iron
and one (1) of compacted graphite iron are addressed. High
temperature nodular iron is alloyed with additional silicon,
molybdenum and sometimes other elements to provide improved
properties at elevated temperatures. Nodular iron is produced by
treating molten iron of appropriate base metal composition with
magnesium. The higher silicon and molybdenum level gives the iron
better resistance to scaling and better dimensional stability while
improving resistance to creep and elevated temperature
strength.
Compacted graphite iron production is similar to nodular iron
with the addition of rare earth elements, but it also requires
another alloying element such as titanium to minimize the formation
of spheroidal graphite. The graphite structure and resulting
properties of the iron are an intermediate between gray and ductile
irons.
Symbols. Not applicable.
Applicability. High temperature resistant cast
iron is used for those applications which require a higher
resistance to heat, resistance to scaling and dimensional stability
at elevated temperatures. Exhaust manifolds and turbo charger
housings are the typical applications for this iron.