. Steel rails; their history, properties, strength and manufacture, with notes on the principles of rolling stock and track design . Fig. 320.—Transverse View at Top of Head, , 50 Dia. (Am. Ry. Eng. Assn.) Fig. 321.—Transverse View at Center ofHead, 70-lb. Rail, 50 Dia. (Am. Ry. Eng. Assn.) 10 per cent solution of nitric acid in alcohol, and microphotographs made, mag-nified 50 diameters. Thus, horizontal, vertical transverse, and vertical longi-tudinal sections were obtained atthe top and at the center of thehead. There will always be somedifference between the structure ofthe cente
. Steel rails; their history, properties, strength and manufacture, with notes on the principles of rolling stock and track design . Fig. 320.—Transverse View at Top of Head, , 50 Dia. (Am. Ry. Eng. Assn.) Fig. 321.—Transverse View at Center ofHead, 70-lb. Rail, 50 Dia. (Am. Ry. Eng. Assn.) 10 per cent solution of nitric acid in alcohol, and microphotographs made, mag-nified 50 diameters. Thus, horizontal, vertical transverse, and vertical longi-tudinal sections were obtained atthe top and at the center of thehead. There will always be somedifference between the structure ofthe center of the head and the por-tion near the surface, but when therail is rolled at a proper temperatureduring the passes, when considerablework is put upon the piece, thisdifference will not be serious. The effect of finishing temper-ature is not fully agreed upon, andmany rolling-mill men feel thatthe properties of the steel dependquite as much on the amount ofreduction in the rolls as upon the finishing Fig. 322. — Pieces for Microscopic Views shown inFigs. 316 to 321. 434 STEEL RAILS * To try to arrive at some conclusion in this matter, a number of tempera-ture readings were taken with both the Fery and Wanner pyrometers andchecked against a thermo-couple at one or two large plants. For steel rails thefinishing temperatures as indicated by the optical pyrometers averaged 1050to 1100° C.;f for structural steel, 950 to 1000° C. And yet such material is notcoarse-grained. (Reheating to such a temperature would give rail steel a verycoarse grain.) A difference of over 100° C. in finishing temperature could notbe detected in the size of grain, but a difference in section could very soon benoticed. Similar results can be reached experimentally by rolling out smallsections at different temperatures. A section heated to 1300° C. and rolledout with 30 per cent reduction showed about the same sized grain as one heatedto 1300° C, cooled to 900°, and rolled out, th
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Keywords: ., bookcentury1900, bookdecade1910, bookidsteelrailsth, bookyear1913
