By industry branch, the union proportion was about one-half of the workers in gray iron
pipe and fittings and steel foundries; three-fourths in gray iron
foundries, except pipe and fittings; and nine-tenths in malleable iron foundries.
In gray iron
, the graphite exists as flakes, whereas the graphite in the imbedded flake matrix of graphite often traps and binds corrosion poducts in place.
Circa 1950, when ductile iron came on the scene at twice the strength of cast gray iron
, there suddenly was less general interest in making high-strength gray iron
The microstructure of the CGI material is such that there aren't the stress risers and fault lines associated with gray iron
, nor are there the thermal requirements characteristic of machining nodular iron.
Seventy percent of the country's casting production is gray iron
for use in the sugar mill, automotive, agriculture, cement and chemical industries.
A continued loss to imports from Eastern Europe is probable, along with gray iron
conversions to ductile iron.
The average weight of gray iron
per light vehicle is forecast to drop to 180 lbs.
The West Allis facility is an automatic green sand gray iron
plant employing 22 salaried and approximately 90 hourly workers.
China continues to produce ingot molds in quantity for blast furnaces, and gray iron
pipe has not been replaced by ductile iron, malleable iron and steel.
Imports of gray iron
castings are forecast to reach 1.6 million tons in 2008, 29% of demand.
Peak production of medium to heavy trucks and freight cars spurred increases in shipments of ferrous castings, but lowering production in these market sectors is forecast to result in declines in gray iron
and steel castings through 2008 of 1.7% and 11.4%.
For gray iron
G3000, we have tensile results of 31 ksi to 34 ksi.