. The Iron and steel magazine. Fig. I. A Rail Section from the upper portion of the ingot with acentral core of in which by liquation the metalloids in the steel areabove the average. A central pipe is also indicated, which may be formedwithout decided liquation. The distortion of the rail head in service shows that thesteel has low limits of cubic elasticity, and is not homogeneous.(See Figs, i and 2.) When the steel is solid, sound and of fine texture, the headdoes not become distorted under the service, though it wearsin the bearing surface and on the side. When the ingot is un-soun
. The Iron and steel magazine. Fig. I. A Rail Section from the upper portion of the ingot with acentral core of in which by liquation the metalloids in the steel areabove the average. A central pipe is also indicated, which may be formedwithout decided liquation. The distortion of the rail head in service shows that thesteel has low limits of cubic elasticity, and is not homogeneous.(See Figs, i and 2.) When the steel is solid, sound and of fine texture, the headdoes not become distorted under the service, though it wearsin the bearing surface and on the side. When the ingot is un-sound and spongy, then the head flattens and crushes under thewheel treads. Rails from the top of the ingots, where by liqua-tion the upper portion contains a higher percentage of carbonand phosphorus, the central core of metal is not soimd andstrong, but fragile, and does not sustain the wheel contact pres-sures as well as the exterior portion of the section. (See Fig. i.) 152 The Iron and Steel Magazine. Fig. 2. Check developed in headof rail, twelve feet in length, afterservice. Sound at the ends. When a decided pipe in the ingot did not occnr in cooling,the repeated pressures of the wheel contacts develop a checkwhich is equivalent to a pipe, the metal immediately over it in the bearing surface stretchingsidewise by its linear elasti-city ; the check widens until aportion of the head becomesdetached from the web ofthe rail, unless fromthe track. (See Fig. 2.) Thesteel in the head is not homo-geneous, either in quality orstructure, and becomes dis-torted as a section, from in-adequate physical propertiesof cubic or elasticity of vol-ume, to sustain and distributethe wheel loads. The splitting of the headin the earlier steel rails was in nearly all cases traced directlyto a pipe in the ingot. These conditions still exist, yet thereare numerous instances in which the pipe did not develop incooling, but does in service, in the unsound metal of the centralcore of steel, as
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Keywords: ., bo, bookcentury1800, bookdecade1890, booksubjectiron, bookyear1898
