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332       .                 METALLURGY   OF   CAST   IRON.
the soft iron was half gone. The soft iron melted sluggishly, and did not hold its form while melting as well as the hard iron. It was very interesting, even if trying to the eyes, to observe the whole process, and now that Mr. West has gone into the whole matter so thoroughly, we will certainly be able to crystallize our ideas and know what we may look for in making up important charges.''
This second paper, aside from presenting several important discoveries made by the author, shows that a chilled body of iron will melt faster and require less heat than a gray body, both having been poured from the same ladles or cast of iron, and that steel proper requires higher heat than cast iron to fuse it; also that remelting of steel in contact with incandescent fuel wholly destroys its original character. Making comparisons of the fusibility of gray and chilled bodies, both of the same composition excepting the combined carbon, was accomplished by the following plan. A heat of chilling or low charcoal iron, designated as heat No. 9, Tables 72 and 73, was caught in hand ladles and then poured into sand and chill moulds, placed side by side. A view of the chill mould and chill roll cast in it is seen at Figs. 58 and 59, page 312. This gives a wholly gray body of iron in the casting coming from the sand mould, and a wholly chilled or white crystallized body of iron from the chill or all-iron mould; both, it is to be remembered, being pouredn the soft pig, and only .68 per cent, in the hard white one. In melting these two pigs under exactly the same conditions, the hard one went first. It held its form well, but in melting ran like water, and was melted beforeiron used as a comparative constant to the hard irons throughout the eight heats. It may be stated that drillings for45 s.	i m.	10 s.	45 s.	i m.	15 s.	nil 3os	nn 458