Bulletin of the Bureau of Standards, 1917 (Classic Reprint)

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Excerpt from Bulletin of the Bureau of Standards, 1917The fundamental importance of the iron-carbon thermal equi librium diagram in the scientific metallurgy of iron and steel and its utility to practical workers have long been realized, and accord ingly this subject has received attention from many points of view and from many investigators during the past two decades.In view of this fact, it might seem super¿uous to add to the existing literature except for the following considerations: Earlier workers have for the most part confined their attention to special portions of the diagram or to disputed questions of theory. Their thermal studies have not been carried out with the degree of accuracy now attainable. They have practically without ex ception employed commercial materials of varying degrees of purity. In two papers published in 1913 1 Prof. H. M. Howe, as a result of a thorough examination of the literature, has fixed the most probable position of the equilibrium lines. His net con clusions are that this calculated line is not entitled to great weight because of the weakness of the evidence, and that much better data are needed, reached with pure materials and with the many causes of error reduced to a minimum. In Table I, compiled from Prof. Howe's papers, are given analyses of the materials used in some of the more important recent investigations. A glance at the table will show the justice of the conclusions quoted above. The analyses are incomplete even for the impurities ordi narily determined and entirely ignore the possible presence of other impurities, such as Cu and Ni, but so far as they go, they indicate a very appreciable degree of contamination by S, SI Mn, elements which we know exert a marked efiect on the critical ranges. It may be said that the iron-carbon diagram has never been worked out with pure iron-carbon alloys. The present paper describes the preparation of a series of high degree of purity, to be used as the basis of a more accurate study of the equilibrium diagram than has heretofore been attempted.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully, any imperfections that remain are intentionally left to preserve the state of such historical works.