. Transactions. suffices first to retard and then to arrest the fall oftemperature, all as shown in Gutowskys curve No. 3, and thento cause a rise to 1,130°. The precipitation of austenite con-tinues to enrich the molten in cementite faster than the meta-stability of this excess of cementite leads to its precipitationand graphitization, with the result that the molten increases in RUFF S CARBO^MRON EQUILIBRIUM DIAGRAM. 449 dissolved eementite content, and towards the end reaches the temperature and carbon content of the molten followa path like QB, solidification naturally accelerating
. Transactions. suffices first to retard and then to arrest the fall oftemperature, all as shown in Gutowskys curve No. 3, and thento cause a rise to 1,130°. The precipitation of austenite con-tinues to enrich the molten in cementite faster than the meta-stability of this excess of cementite leads to its precipitationand graphitization, with the result that the molten increases in RUFF S CARBO^MRON EQUILIBRIUM DIAGRAM. 449 dissolved eementite content, and towards the end reaches the temperature and carbon content of the molten followa path like QB, solidification naturally accelerating and com-pleting itself on reaching B. The arrival of the molten at B causes it to deposit layers ofcarbon content E^ per cent.; but yet the fact that the aver-age combined carbon content of the whole, per cent, is farless than E, is, indeed, only slightly above E^ per cent., isvery easily understood. For (A) the earliest deposited layers,deposited before selective freezing had enriched the molten. Fig. 5.—The Course of the Molten during the SolidificationOF Gutowskys Cast-Iron No. 3, on the assumption that theeutectic temperature is 1,125°. (24.) materially, were, of course, very poor in carbon; and diffusionhas had insufficient time to enrich them very greatly; and (B)all the intermediate layers deposited during the progressiveenrichment of the molten up to B have been deposited with adissolved carbon content less than E, per cent, and these,too, have been only incompletely enriched towards E by diffu-sion during the limited time. (27) The Eutectic Temperature may he Above 1,130°.—Nextassuming that the eutectic temperature is above 1,130°, say at 450 RUFF S CARBON-IRON EQUILIBRIUM DIAGRAM. 1,135°, let US represent the course of the molten of alloy No. 3with a very different temperature scale, as in Fig. 6, assumingthe same temperature-course as found bj Gutowsky and shownin Fig. 5. With this temperature assigned to EB, the observedcourse of the molte
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