. The Street railway journal . gredients ofsteel such as carbon, sulphur, phosphorus and, to a less degree,silicon and manganese, according to their resisective temperaturesof solidification. These tend to concentrate at the center and upperportion of the ingots where the metal last solidifies. Fluid com-pression tends to prevent segregation and produces ingots which aremore homogeneous than can otherwise be made. As piping and segregation tend to affect the center ofingots and consequently of the shafts made from them, in order tofree the latter from any ill effect that might occur from these
. The Street railway journal . gredients ofsteel such as carbon, sulphur, phosphorus and, to a less degree,silicon and manganese, according to their resisective temperaturesof solidification. These tend to concentrate at the center and upperportion of the ingots where the metal last solidifies. Fluid com-pression tends to prevent segregation and produces ingots which aremore homogeneous than can otherwise be made. As piping and segregation tend to affect the center ofingots and consequently of the shafts made from them, in order tofree the latter from any ill effect that might occur from these causes,it is custoinarj to make them hollow by boring. The removal of As before stated, in order that the metal should be sufficientlyworked to give it strength and toughness, the best practice re-quires that the ingot should be at least twice the diameter of thefinished forging. It is also made from twenty-five per cent tofifty per cent longer than otherwise would be necessary to take careof piping and segregation. E==E 3: 3. FIG. 2.—SHAFT UNDER HYDRAULIC PRESS. this probabh imperfect portion improves steel shafts greatly, pro-vided they are treated subsequently so as to increase the elasticstrength of the remaining metal. The first hollow shafts of this character were supplied to thiscountry by Fried. Krupp, of German}, but his were made of cruci-ble steel and after boring were oil tempered to restore the strengththat was taken from them by boring. The most satisfactory of accomplishing the result sought for is that known ashollow forging, which was introduced into this country fromEngland by the Bethlehem Iron Company when it built its presentforging plant. As the walls of hollow shafts are comparatively thinand yet must do the work originally intended to be performed bythe solid forging, the metal must be without flaw or defect of anykind, homogeneous throughout, and thoroughly worked to give itstrength. For this purpose, therefore, only fluid compressed o
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectstreetr, bookyear1884
