EFFECTS OF ADDING PHOSPHORUS TO MOLTEN IRON. 227
poured onto it, while R. I. refers to the metal free of the phosphorus addition.
AH the bars were cast on end and tested i 2 inches between supports. Those of tests Nos. i and. 2 were made from patterns i}4 inches in diameter and the balance from i//£ inches diameter. The strength column of Table 33 shows the breaking load reduced to strength per square inch by the method shown on page 476. Each test shown is an average of from two to four bars. Tensile tests were made of tests Nos. i, 2, 3, 4, 5, and 6. The i^-inch bars with the phos-'phorus addition of No. r pulled 27,640 pounds, whereas the regular broke at 15,130 pounds, showing that the addition of phosphorus nearly doubled the strength of the iron in this case. Test No. 3, i^-incli bars, averaged 23,790 pounds, whereas No. 4 averaged 1.7,617 pounds. Bars of test No. 5 averaged 26,070, and those of No. 6 16,890 pounds. A study of Table 33 will show that all tests were greatly strengthened by the slight addition of phosphorus to the molten iron, excepting test No. ro. The author believes this is due to the high silicon iron..
A study of the analysis of Table 33 shows that the addition of -phosphorus drove out or decreased the silicon, manganese, and total carbon, the phosphorus acting as a (lux to drive out oxides or impurities so as to leave a greater percentage of metallic iron in the higher phosphorus iron than existed in the regular iron, as is seen in the last column, of the analysis at T. I. The efleet of decreasing impurities, as shown, is in keeping with the treatment of Chapter XXXIV. Aside from the decrease of the impurities we find that the increase of combined carbon shown, caused, by increas-ron to the limit of its absorption. Views of the fracture of the above bars, described in Tables 31 andthe so-The philosophical explanation of this extraordinary effect i my opinion, to be found in the fact that the f erro-manganesu .ğR. C. Hindiey, M. Hoskins, Harvard College, Havemeyer University, Henry Hiels Chemical Co., Isabella Furnace, Iron Gate Furnace, Iroquois Iron Co., Illinois Steel Co., Jefferson Iron Co., Kittan-ning Iron & Steel Co., C. A. Kelly Plow Co., Lebanon Furnace, Longdale Iron Co., Lackawanna Iron & Steel Co., Logan Iron........................ 16,720 " t-