Classification of cast irons

The classification of cast iron is often made according to its material properties ... 

Table 3.1-79 Classification of cast irons according to commercial designation, microstructure and color of fracture surface [1.89]...

More recently, attempts have been made to correlate mathematically the chemical composition of natural waters and their aggressivity to iron by direct measurements on corrosion coupons or pipe samples removed from distribution systemsThis work has been of limited success, either producing a mathematical best fit only for the particular data set examined or very general trends. The particular interest to the water supply industry of the corrosivity of natural waters to cast iron has led to the development of a simple corrosion rig for the direct measurement of corrosion ratesThe results obtained using this rig has suggested an aggressivity classification of waters by source type i.e. 

FERROCHROMIL M. An alloy, composed principally of iron and chromium, used as a means of adding chromium to steels How. medium, and high-carbon I and cast iron. Available in several classifications and grades, generally containing between 60 to 705( chromium, in crushed sizes and lumps up to 75 pounds dial readily dissolve in molten steel. 

The bronze samples were obtained in 30.5 cm x 30.5 cm sheets from the C.R. Hills Co. (Berkley, MI). The bronze alloy was cast as Alloy 220 with 90% copper and 10% zinc by weight, with trace lead and iron impurities. It was in sheet rolled form at 18 gauge (1.00 mm thickness) and with a density of 8.80 g/cm. Historically, bronze was classified as copper/tin alloy with a minimum 10% by weight tin, while brass was a copper/zinc alloy with at least 10% zinc. The contemporary classification of "bronze" has been expanded to encompass a much wider range of copper alloys with bronze-like structures, properties, and color, but which contain no tin. Thus, although it is commercially classified as bronze, the sample utilized in this work was historically brass. 

The assessment is directed at ferrous materials (steels, cast irons, and high-alloy stainless steels), hot-dipped galvanized steel, and copper and copper alloys. Summation of the individual ratings produces an overall corrosivity classification into one of four categories with scores less than -10 indicating a highly corrosive soil and positive values (>0), a noncorrosive environment (Table 10.7). It has been pointed out that sea or lake beds cannot be assessed using this worksheet. 

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