Hearth Process Research Articles

物理化學より見たる平爐操業諸過程の關連性について(VII)

How the steel bath becomes not gasious in final period of melting process, and how the steel bath gets the standard amount of Si, Mn, C are discussed.Thus the five objects to remelt steel scrap are all obtained. From the first report to the seventh report, the mutual correlation of the entire procedure in the acid open hearth process is physically and chemically analysed, and we knew that the whole operation which is systematised with the accumulation of experiences is generally reasonable and we are obliged to pay our respects to our senior's merit.

電氣爐に依るリムド鋼製法に關して

We have successfully made rimmed ingot by Heroult furnace, using the reducing slag, which is proper to electric furnace, instead of the oxydizing slag Proper to open hearth process. Advantages of this method;-1. Higher stability of the process.2. Far better yield of Fe-Mn.3. Higber availability of bad scrap.4. Good qualitfy of product.we think that this method has the good prospect to be the best way to make sound semi-killed ingot without using Fe-Si or Al, and therefore we have a vague idea that this may be able to cultivate the new field of rimmed ingot unknown to open hearth.

Calendar of Discovery and Invention

April 10, 1864.—The modern process of manufacturing open hearth steel was started by PierreEmile Martin, who melted together pig-iron, scrap, and iron ore in a Siemen's regenerative furnace. Martin's French patent was taken out on April 10, 1864. Two hundred years ago, R6aumur described the conversion of wrought iron into steel by fusing it with pig-iron, but his experiments never went beyond the laboratory stage. The open hearth process was introduced into America in 1868. In 1880 that country produced 1,074,000 tons of Bessemer steel, and 110,000 tons of open hearth steel. Forty years later these figures had increased to 8,883,000 tons of Bessemer steel, and 32,672,000 tons of open hearth steel, the total production being nearly equal to half a ton of steel per head of population.

Elementary Text-book of Metallurgy

THIS book is intended, for those who are commencing the study of metallurgy, as a kind of preparatory course to that of Prof. Roberts-Austen, as given in his “Introduction to the Study of Metallurgy,” which the student is advised to read after digesting the contents of Prof. Sexton's manual. The work is got up in good style by the publishers, and printed in a clear and distinct manner. With the general arrangement there is very little to complain of; but the same by no means can be said of the subject-matter, which contains many errors, and the definitions are often expressed in such crude language that a student might be easily misled in taking his first lessons in metallurgy from its pages. The following examples may be cited:—P. 3: Malleability. This is the property of being expanded into sheets. Ductility: Tnis is the property of being drawn into wire. A small quantity of antimony in lead is said to make it quite brittle. P. 4: Lead may be drawn into wire if means be taken to prevent the metal being subject to stress. P. 5: With regard to tensile testing, the author says that elongation takes place mostly near the point of fracture. P. 46: There are but two neutral substances in general use, graphite and chrome iron ore. P. 89: Fluor spar is said to be used to increase the quantity of slag. On pp. 92 and 121: C below ˙5 is termed wrought iron, and steel when C is between ˙5 and 1˙5; while on p. 110, it is stated that, in puddling, the carbon is reduced to ˙1 per cent.; and also that during the melting-down stage there is little chemical action. P. 111: Puddled bloom is chemically wrought iron with intermingled slag. P. 123: Steel is made by carbonising malleable iron. P. 128: Mild steel, not more than ˙5 per cent, carbon, does not harden when heated and quenched in water. P. 134: The slags from the acid Bessemer process are very basic silicates of iron and manganese. P. 138: In Open Hearth process it is stated that the iron ore should be as free as possible from silica, whereas the Spanish hematite usually employed is very siliceous. P. 143: The strength increases as the diameter of the wire decreases. Also cake or tough copper may contain any amount of impurities. P. 223: An alloy of 80 per cent, copper and 20 per cent, zinc is called red brass. P. 229: Electro refining of copper; the anode is a thin sheet of copper; the cathode is a bar of blister copper. P. 230: The passage of the electric are through the carbons produces a very high temperature. It is a great pity that a work which has been so judiciously compiled as the present one should be marred by so many mistakes, when by a more careful supervision of the proof sheets they might have been easily detected and corrected.