. Transactions. sm. Afterinvestigating, they reported in effect that the evidence submitted indi-cated that the carburizing results were influenced by the condition ofthe steel as made and offered to submit for check, samples of steel usedby Mr. Boylston^ in connection with his work on the value of differentdeoxidizers. This was done, and it was found that the samples from theingots deoxidized with ferromanganese, ferrosilicon, and ferrocarbo-titanium gave a normal hj^pereutectoid zone after carburizing, while thesamples from ingots deoxidized with carbon-free ferrotitanium and alum-inum gave
. Transactions. sm. Afterinvestigating, they reported in effect that the evidence submitted indi-cated that the carburizing results were influenced by the condition ofthe steel as made and offered to submit for check, samples of steel usedby Mr. Boylston^ in connection with his work on the value of differentdeoxidizers. This was done, and it was found that the samples from theingots deoxidized with ferromanganese, ferrosilicon, and ferrocarbo-titanium gave a normal hj^pereutectoid zone after carburizing, while thesamples from ingots deoxidized with carbon-free ferrotitanium and alum-inum gave an abnormal hypereutectoid zone, indicating a different con-dition of the steel. Figs. 43 and 44 show an abnormal and a normal casewith different deoxidizers. All samples on this test were packed in thesame carburizing pot. ^ iv ■ li- ^< ■ i ■ . .■ ^l *.-<<.rH-^ f-Xi| •> . .-4f ; ,.-r V : ■ ^■O^V^-V^*^ 77--^:^/^ ^t^- ;. V- ,, ^ vO-^ . •v- ^^^:,-:>.^^^. Fig. 43.—Boylston test piece, hy-pereutectoid zone; specimen from INGOT deoxidized WITH ALUMINUM. X 200. Fig. 44.—Boyl,ston test piece,hypereutectoid zone; specimen fromingot deoxidized with ferromanga-NESE. X 200. * Etching, by cupric reagents, of the free ferrite formed by the breakingdown of the hypereutectoid zone of abnormal steel showed no indicationsof phosphorus concentration. It is believed by the writers that thecarburizing (24 hr. at 925° C.) is sufficient to permit of the phospho usdiffusion, as all efforts to obtain evidence of segregated phosphorus aftercarburizing have failed, although the ghost lines still persist. Figs. 45 and 46 show a manganese-sulfide inclusion in the hypereutec-toid zone after carburizing, with no evidence of change in the normallamellar pearlite. The fact that manganese sulfide introduced intonormal steel (Fig. 29) caused the breaking down of the pearlite aftercarburization in the portion of the metal surrounding the inclusion is not Iron an
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Keywords: ., bo, bookcentury1800, bookdecade1870, booksubjectmineralindustries
