Cast irons white iron

There are two basic types of cast iron white, and grey. The phases in white iron are a and FejC, and it is the large volume fraction of FejC that makes the metal brittle. The name comes from the silvery appearance of the fracture surface, due to light being reflected from cleavage planes in the FejC. In grey iron much of the carbon separates... 

C < 4.5 Cast iron Gray iron White iron... 

The most important of all materials which enter into the construction of chemical apparatus is iron. It is usual to distinguish three kinds which are used in the arts and manufactures, viz., cast-iron, wrought-iron, and steel. But in order to obtain the best technical effects from them it is necessary to make further distinctions, and to consider their properties more in detail, particularly when they have to be used for special purposes. Ordinary grey cast-iron, as it comes from the blast furnace, contains from 2 to 4white cast-iron the carbon is chemically combined with the iron. It may contain manganese in varying quantities, from 1 to over 20 per cent. In steel, the quantity of carbon is more than per cent. in wrought-iron, less. 

C (Mond process). The silver-white metal is ccp. The metal is not tarnished by air but is attacked by acids (except cone. HNO3). It is resistant to Fj. It is used extensively in alloys, particularly in steels and cast iron and as a coinage metal. Used in glass (green) in catalysts (particularly for hydrogenation). Western world production 1981 662 000 tonnes. 

A second, more recently developed use for strontium metal is as an inoculant in ductile iron castings. Inoculants provide nuclei upon which graphite forms during the sohdification of cast iron, thus preventing the formation of white cast iron. Elkem Metals Company has commercialized a range of fine-sized foundry inoculants for iron castings. These inoculants, called superseed, are ferrosiUcon alloys containing 50 or 75% Si, 0.8% Sr. Most of the balance is iron. 

Alloyed white cast irons fall into the second categoiy. This group includes the nickel-chromium grades known as Ni-nards (Durman,... 

White cast iron is brittle and difficult to machine. It is made by controlling the composition and rate of solidification of the molten iron so that all the carbon is present in the combined form. Very abrasive- and wear-resistant, white cast iron is used as liners and for grinding balls, dies, and pump impellers. 

White cast iron is very hard (from 400 to 600 DPN) and brittle. All white cast irons are very difficult to machine and usually are finished by grinding. Table 3.3 gives properties of the four principal types of white cast irons. 

This type of cast iron is made by high-temperature heat treatment of white iron castings. The mechanical properties of malleable cast irons are given in Table 3.1 usually they are applied to the fabrication of conveyor chain links, pipe fittings and gears. 

The white cast irons and their low alloys have good abrasion resistance properties [2,3]. White cast irons are used for grinding balls, segments for mill liners and slurry pumps. In the ceramic industry they are used for muller tyres and augers in the pulp and paper industry for attrition mill plates and chip feeders and in the paint industry for balls for grinding pigments. 

The corrosion resistance of unalloyed and low-alloy flake, nodular, malleable and white cast iron is comparable to mild- and low-alloy steel. However, these cast irons have a major advantage over steel namely, greater cross section or wall thickness than steel. Consequently, they have a... 

Weiss-gUldenerz, -giiltigerz, n. argentiferous tetrahedrite, -guss, m. white metal white malleable cast iron, -hitze, /, white heat, -kalk, m. pyrolignite of lime (crude calcium acetate) fat lime, white lime, -keraguss, m. white-heart malletxble iron. 

In general, unalloyed grey or white cast irons possess no useful resistance to dilute mineral acids. In very dilute acids the presence of air, or other... 

Chemical plant Sheet-iron (groundcoats) Sheel iron (white) Sheel iron (acid resistant black) Cast iron (semiopaque)... 

Abrasion-resistant white cast irons, molybdenum in, 17 17 Abrasive Grain Association (AGA), silicon carbide standards by, 22 537, 538 Abrasive materials, phenolic resins in,... 

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