Implementation of Metal Casting Best Practices - EERE - U.S. ...

E. Iron Foundry-1
Plant Profile
Iron Foundry-1 is a large facility, occupying approximately 145,000 square feet on
approximately two city blocks of land. The facility employs 200+ hourly employees. Castings
produced at this foundry range in size from 1 to 110 pounds and are used in automotive, valve,
and industrial machinery applications. The foundry produces either a gray iron base chemistry or
a ductile base chemistry from a single water-cooled cupola at a rate of 15-20 tons/hour for 8-10
hours per day. The cupola uses a 1,000 ºF recuperative hot blast with oxygen injection.
Gray iron has a high percentage of carbon present in the form of flake graphite. Ductile iron has
essentially the same carbon levels as gray iron along with a small amount of magnesium. The
carbon in ductile iron thus forms into small spheres and produces a metal with good ductility,
stiffness, strength, and shock resistance. 54 When producing gray iron, the iron leaves the cupola
and goes directly into an induction holding furnace. During the weeks that the ductile iron base
chemistry is being produced, the molten iron is desulphurized using a continuous lime-fluorspar
porous plug ladle prior to being transferred to a ductile iron-specific induction holding furnace.
Sulphur levels must be reduced from the typical 0.08% leaving the cupola to approximately
0.01% in order to economically produce ductile iron.
Before a mold is made, the facility models all new designs using AFS Solidcast and Flow
Modeling/Novacast tools. The facility uses green sand as its molding medium. Sand is mulled in
one of the two batch mullers with automatic control of compactability. For core making, the
facility utilizes the shell, warm box, or cold box process depending on the economics and/or the
core design. Compressed air is supplied from two 400 hp compressors with outside air intake.
All air passes through refrigerated driers, which reduces the dew point to approximately +40º F.
The air for the cold box process is dried to -40º F. Once the molds are poured and the castings
are shaken out, the facility cleans the castings using one of the three shot blasting machines and
then moves them to snag grinding and/or table grinding workstations.
Onsite Assessment
During the site visit, the facility’s foundry manager accompanied the assessment team. The
agenda for the site visit followed the same format as the others, beginning with a meeting in the
morning for the assessment team to obtain an understanding of the research implemented at the
facility and to provide an overview of the tools and services offered by the ITP BestPractices
subprogram. As was common throughout this project, the facility was unaware of these tools and
services, but expressed interest in pursuing both an IAC assessment and learning about the suite
of BestPractices tools. After the morning meeting, the assessment team was guided on a tour of
the facility by the foundry management to see the implemented R&D in action and also to make
recommendations on potential areas for improvement.
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