The Iron and steel magazine . to indicate that they were made bydifferent processes. The method I use is as follows: Specimens of steel are secured of about i\ inches square. As many as are to be tested are placed in a large beaker,along with a standard known to be crucible steel. For eachspecimen 100 cubic centimeters of dilute sulphuric acid is used(90 cubic centimeters water and 10 cubic centimeters acid)together with 3 grains of permanganate of potash for eachspecimen. Thus, if ten specimens are to be etched, use 1 liter of diluteacid and 30 grams of permanganate crystals. 1 ii /./<
The Iron and steel magazine . to indicate that they were made bydifferent processes. The method I use is as follows: Specimens of steel are secured of about i\ inches square. As many as are to be tested are placed in a large beaker,along with a standard known to be crucible steel. For eachspecimen 100 cubic centimeters of dilute sulphuric acid is used(90 cubic centimeters water and 10 cubic centimeters acid)together with 3 grains of permanganate of potash for eachspecimen. Thus, if ten specimens are to be etched, use 1 liter of diluteacid and 30 grams of permanganate crystals. 1 ii /./< ///;/! Method Samples remain at room temperature over night and inthe morning, if solution is colored red or brown from mangamcompounds, boil until decolorized, adding more acid if necessary. When solution is free from red or brown colors the samples arewashed in water and wiped to remove carbonaceous matter. They can then be examined by the unaided eye. The open-hearthand Bessemer steel will be etched in grooves, in the. Fig. 2 direction of rolling; the cross section at the edge wrill be honey-combed and feel rough to the touch. The crucible steel will not be etched in grooves, but willshow a close structure with perhaps an appearance of havingminute pittings. All edges of the crucible steel will be comparatively smooth. These structures being dead black, it is necessary (whenexamining them microscopically) to polish on a felt disk thathas been dressed in 10 M. P. carborundum or rouge. 386 The Iron and Steel Magazine OPEN-HEARTH STEEL CASTINGS.* — IV By W. M. CARR {Continued from page 301) Manipulation of Heats in Acid Practice /^ IVEN an acid-lined hearth and stock for melting purposes,^* u the next step will be to consider some of the changes thattake place in the conversion of the materials charged, into has been mentioned, the only elements that are confinedwithin stated limits are the sulphur and phosphorus. Consid-erable latitude remains in making up the cha
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Keywords: ., bookcentury1800, bookdecade1890, bookidironsteel, booksubjectiron
