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PLANT VISIT |
Rochester Metal Products, Disa Plant
Rochester Metal Products, located in Rochester, Indiana, is a gray and ductile iron foundry which utilized Hunter and Disa green sand molding and electric melt. The company received its QS-9000 certification in November 1997. The plant described herein is the Disa Plant, which is strictly a ductile iron jobbing shop.
Core
Production
The core room uses Isocure resins, at a level between
1 and 1.3 percent, and DMEA gas. Sand mixing is achieved
using a Redford Carver Mark I high speed traveling batch
mixer. The sand used is a 60 GFN round grain silica. The
prepared sand is delivered to two Hottinger FC 16-core
machines and one CMI CB26 Horizontal Core Machine.
Molding
The new sand used is a 60 GFN round grain silica.
Sand cooling is employed using water sprays, aeration,
and a fluidized bed cooler. The sand temperature drops
are approximately 150-200oF, producing an
average sand temperature at the muller of 110oF.
The sand is prepared at a rate of 75 tons per hour in two
B&P 100B speed mullers equipped with Hartley
Compactability Controllers. This system feeds sand to two
2013B Mark V Disas which are equipped with core setters.
The goal for mold production is 350 molds per hour at 85%
uptime and the average casting weight is 5-7 pounds.
Melting
The iron grades produced are 60-40-18, 65-45-12,
80-55-06 and 100-70-03. The shop is approximately 60%
ferritic and 40% pearlitic. Primary melting is done in
two 30-ton line frequency BBC coreless induction furnaces
and the tap temperature from these furnaces is 2630-2650oF.
The holding furnace is a 30-ton Ajax Vertiplex vertical
channel furnace with 20 useable tons. The average base
iron chemistry is carbon 3.75-3.90%, silicon 1.65-1.85%,
sulfur 0.01-0.02% and the manganese is 0.32-0.38%.
Pouring and
Treating
The two pouring furnaces are 10 ton Duca Pressure
Pour vertical channel induction furnaces equipped with
Selcom Laser Pour systems, which have a usable capacity
of 7 tons. The stopper rods used in the system are
alumina graphite and the nozzles are fused silica with a
diameter of 1-1/8 inches. The average final chemistry is
carbon 3.60-3.80%, silicon 2.45-2.65%, and magnesium
0.030-0.037%. Copper is used as the pearlite stabilizer
for the grades 80-555-06 and 100-70-03 and the average
pour temperature is 2525 to 2575oF.
Ductile treatments are done in an open-top 4500-pound ladle with an alloy pocket using 5% MgFeSe and cover steel. Any required alloys are added at this time using a treatment temperature of 2650-2700oF. Using this method Rochester treats and pours 250-275 tons per day and the average mold cooling time is 45 minutes.
Inoculation
All inoculation is done in-stream. The units used are
Foseco MSI System 90 and the normal inoculation is 7
grams/second using Foseco I-90. Certain jobs may require
a higher level of inoculation.
Laboratory
Facilities
All ductile iron chemistry samples are run on a
Spectro LAVMB08B spectrograph. Carbon and sulfur
chemistries are run on a Leco CS-300 carbon determinator.
Each tap is qualified by polishing an in-mold coupon and
test bars are pulled in-house. A sand lab is available to
run necessary tests.
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