File:Transactions (1871) (14592751847).jpg

Identifier: transactionsmining47amer (find matches)
Title: Transactions
Year: 1871 (1870s)
Authors: American Institute of Mining, Metallurgical, and Petroleum Engineers
Subjects: Mineral industries
Publisher: New York (etc.)
Contributing Library: Gerstein - University of Toronto
Digitizing Sponsor: University of Toronto

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escence point of steels,but does not lower it below 550° C. Mfiller 3l found that the arrestpoints of iron are lowered from 60° to 80° by the presence of copper.This explains why a steel containing copper is more readily hardenedthan one not containing that element, and in this respect the effect ofcopper resembles that of carbon, though to a less extent. Tensile Tests.—Tensile tests were made upon: 1. Steel as forged,for which test pieces were turned from the forged bars. 2. Steelannealed. Eight pieces, in the rough before turning, were annealed 27 Journa1 of the Iron and Steel Institute, vol. lx. (1901, II), p. 115. *8 Transactions of the American Electrochemical Society, vol. xvi., p. 246 (1909). 29 Stahlund Eiseii, vol. xxvi., No. 23, p. 1444 (Dec. 1, 1906). 30 Journal of the Iron and Steel Institute, vol. lxxiv. (1907, II), p. 13. 31 Stahl und Eisen, vol. xxvi., No. 24, p. 1493 (Dec. 15, 1906).vol. xlvii.—18 546 THE INFLUENCE OF COPPER UPON STEEL. TEMPERATURES, CENTIGRADE.
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Fig. 22.—Cooling Curves of Copper Steels. THE INFLUENCE OF COPPER UPON STEEL. 547 in a gas furnace in a sealed muffle so as to exclude air so far as pos-sible. The temperature was raised very slowly to avoid local over-heating. Finally, after two hours the maximum temperature of 820°,as measured by a Le Ohatelier thermo-couple, was reached. Theeight bars were all annealed at the same time, so that each bar wassubjected to exactly the same conditions. The bars were thenallowed to cool in the furnace over night. The test pieces for thesecond series of tests were turned from this annealed steel. The testpieces were of the shape and had the dimensions shown in Fig. 23.The diameter was measured accurately three or four times at differentpoints with a micrometer gauge and the mean of these results wastaken. An electrically driven 100,000-lb. Tinius Olsen testing ma-chine was used for pulling the bars. Photographic views of the testpieces after fracture are shown in Figs. 24 and 25. We ha

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