. Railway mechanical engineer . per cent carbon con-tent was used as a filler. After allowing the tire to cool to the room temperature it was marked off in sections beginningat the center of the weld, and extending beyond its end, asshown in Figs. 2 and 3. The sections were then cut oft in apower hacksaw, polished, etched and photographed. The etching showed that it was advisable to use tliree testpieces per section, and these were marked off, as shown on Tire tobe tested Tensile strength lb. Elongation in 2 , 11-1 per cent Reduction of area per cent Carbon content 765 per ce
. Railway mechanical engineer . per cent carbon con-tent was used as a filler. After allowing the tire to cool to the room temperature it was marked off in sections beginningat the center of the weld, and extending beyond its end, asshown in Figs. 2 and 3. The sections were then cut oft in apower hacksaw, polished, etched and photographed. The etching showed that it was advisable to use tliree testpieces per section, and these were marked off, as shown on Tire tobe tested Tensile strength lb. Elongation in 2 , 11-1 per cent Reduction of area per cent Carbon content 765 per cent Manganese 707 per cent Phosphorus 047 per cent Sulphur-, 037 per cent Silicon 239 per cent -A. S. T. per per per centXot over .75 per centNot over .05 per centXot over .05 per cent per cent the lines on Fig. 4, which also shows the location, markingand hardness numbers obtained from Brinell and scleroscopetests. These test pieces were marked to include, as far as could. Fig. 2—Tire Marked off in Sections. be seen, the same structure as shown by the coloration pro-duced by the etching in Fig. 5, it being desired to obtain anumber of test pieces from each type of zone. For example,it was thought tliat test pieces 4, 7, 10, 13 and 15 (Fig. 3)would probably give nearly the same results, but quite differ-ent from test pieces 6, 9, 12 and 14, which were in an entirelydifferent zone, as shown by the etching. The numbers in Fig. 2 were the ones for the original testpieces, and may be partly seen in Fig. 3, stamped into thesections. The white numbers in Fig. 4 are the ones later de-cided on, and which are used throughout this article. It appears from Fig. 5 that the changes o* =t-*-e indi- 104 February, 1918 RAILWAY MECHANICAL ENGINEER 105 cated may be divided into four principal zones. These arezone .1, the added material; zone B, the darkest one whichhas the tinest grain, having been heated above the criticalrange and rapid
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectrailroadengineering
