This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1908 Excerpt: ...argues that, as these pine-trees grew in cooling through region 2 of Fig. 1, p. 463, no graphite was precipitated, because if any had been, it should be visible in these pine-trees. Next, if no visible quantity of graphite is precipitated, is not that an indication that there is no considerable decrease in the ...
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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1908 Excerpt: ...argues that, as these pine-trees grew in cooling through region 2 of Fig. 1, p. 463, no graphite was precipitated, because if any had been, it should be visible in these pine-trees. Next, if no visible quantity of graphite is precipitated, is not that an indication that there is no considerable decrease in the solubility of carbon in presence of graphite in cooling through region 2? But, if the solubility were considerable, then there ought to be a considerable decrease of it and a considerable precipitation of graphite. The absence of this precipitation, then, is a suggestion that, even at this high temperature, the solubility of carbon in presence of graphite is small. Beyond inferring that the solubility of carbon in presence of graphite is probably less than others have believed, we may here begin to suspect that it is exceedingly small, or perhaps even nil, even at high temperatures. This observation of Goerens and Gutowsky gives us a hint in that direction. The absence of fine particles of graphite from some graphitic irons just noted gives us another such hint. On the other hand, our present theory implies that the first step in the now well-established change of graphite into cementite is the dissolving of that graphite in the austenite, to be followed by reprecipitation of the carbon as cementite. But the rapidity with which this change occurs certainly suggests that this dissolving of graphite must go on rapidly, and hence that the solubility of graphite is considerable. Or is our theory wrong? 49. Solubility at 700. In 43 we inferred from case 5 of Table I. that the solubility at 700 ought to be 0.28 per cent, or less. Applying expression (6) to case 19 of Table I., we find a number very near to this, 0.31 per cent. Therefore, we ma...
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