. Microstructure of changes accompanying the annealing of cast bronze (Cu88, Sn 10, Zn 2). . a, B-29, series 2a, heated one hour at 8oo° C;5X. The recrystallized layer shows just be-neath the protective copper coating on thesurface and lining the central hole b, B 3s-3, series 2b, heated eight hours at 400° C;100 X. c, B 36-1, series 2b, heated two hours at 600° C; 100X d, B 37-4, series 2b, heated eight hours at Soo° C; 100X Fig. 3.—Samples annealed after the surface layer was distorted by machining. The cold-working of the surface layer is practically the same in b, c, and d, since the same
. Microstructure of changes accompanying the annealing of cast bronze (Cu88, Sn 10, Zn 2). . a, B-29, series 2a, heated one hour at 8oo° C;5X. The recrystallized layer shows just be-neath the protective copper coating on thesurface and lining the central hole b, B 3s-3, series 2b, heated eight hours at 400° C;100 X. c, B 36-1, series 2b, heated two hours at 600° C; 100X d, B 37-4, series 2b, heated eight hours at Soo° C; 100X Fig. 3.—Samples annealed after the surface layer was distorted by machining. The cold-working of the surface layer is practically the same in b, c, and d, since the same depthof lathe cut was used for each; all are etched with ferric chloride Micro structural Cast Bronze 13 VI. DISCUSSION OF RESULTS1. INCREASE OF CRYSTAL SIZE It is impossible to make any direct measurements of the crys-tals during the process of annealing, inasmuch as such measure-ments necessitate the preparation of a polished plane surface forobservation. The sawing, grinding, and polishing required inpreparing this surface will be sufficient disturbance as to cause arecrystallization of the surface metal during the subsequentannealing. Primrose 6 reports an increase in crystal size uponheating this bronze to 5000 C, but gives no substantiating evi-dence. Portevin,7 by observing the relation of the bou
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Keywords: ., bookcentury1900, bookdecade1910, bookpublishernatio, bookyear1916
