. Steel rails; their history, properties, strength and manufacture, with notes on the principles of rolling stock and track design . ortion. The cavity in the top of this view is a drilled hole. On one side ofthe head a cavity which did not show on the surface, but indicated markedbreaking down of the metal, was revealed. The metal, however, is more uni-form throughout this rail than was the case in the rail of the preceding figure. View 2 shows the grain at the center of the head; view 3, like \aew 3 ofFig. 268, is taken at the end of the crack. It shows the finer grain and distor-tion of the
. Steel rails; their history, properties, strength and manufacture, with notes on the principles of rolling stock and track design . ortion. The cavity in the top of this view is a drilled hole. On one side ofthe head a cavity which did not show on the surface, but indicated markedbreaking down of the metal, was revealed. The metal, however, is more uni-form throughout this rail than was the case in the rail of the preceding figure. View 2 shows the grain at the center of the head; view 3, like \aew 3 ofFig. 268, is taken at the end of the crack. It shows the finer grain and distor-tion of the same, and shows as well the further distortion of the metal at the INFLUENCE OF DETAIL OF MANUFACTURE 393 end of the crack as a sort of tearing action. The end of the crack is at thecorner of the picture; the further direction of progress of the failure is shownby the black defects extending across the photograph. A longitudinal section of this rail made on portion G showed slag lines, asin the rail of Fig. 268, somewhat most abundant at the point q, though the num-ber was not so great as in the i-ail of the preceding View 3. Cross Section of point H,i., Mag. 100. Fig. 268 \ f » f ,v ) ;•■■■ I • i I I I. »• k . • • • View 4. Longitudinal Section on Top of Portion B,Mag. 50, Head. (Continued.) * The deleterious influence of slag inclosures in steel has perhaps escapedattention to some extent owing to the fact that in ordinary tensile tests, takenin a direction parallel to that of rolling, these inclosures only occupy a verysmall proportion of cross-sectional area and possess a tapered shape which allowsof gradual distribution of the stresses imposed on the material. If, however, weconsider the case of transverse stresses, or of shock or vibration, it will be seenthat these inclosures will be fractured as soon as the metal undergoes any materialdeformation, and then each such inclosure practically represents an internal * Slag In
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Keywords: ., bookcentury1900, bookdecade1910, bookidsteelrailsth, bookyear1913
