Die Gichtgasreinigung als eine Einrichtung der Wärmestelle hat nicht nur die Reinigung des Gases zum Ziel, sondern bezweekt auch die Abkühlung und die Drucksteigerung des Gases. Darum ist der Feinreinigungs-Desintegrator günstiger als der elektrische Gaswascher, bei dem noch Abkühlungs-und Drucksteigerungseinrichtungen nötig sind.
Im Showa-Stahlwerk besteht die Feinreinigung des ganzen Gichtgases aus dem Theisenwascher und dem Dinglerwascher und dieses feingereinigte Gas wird von vieleh Werken mit gutem Erfolg benutzt. Der Staubgehalt des feingereinigten Gases ist unter 0.02gr/cm³. Da man bei Showa derart feingereinigtes Gas herstellte, gingen alle Arbeiten glatt vonstatten und der Wirkungsgrad der Wärmeverbraucher, z. B. Kessel und Winderhitzer stieg, ferner verminderte sich die Verbräuchs a e. Das Ueberschussgas wird von den Koksöfen und dem Stahlwerk verbraucht, Man benutzt also das anfallende Gichtgas in der ganzen Eisenhütte wirtschaftlich und rationell.
Der Gasdruckregler ist unentbehrlich für die Regulierung der Gasverteilung und fur die Verbesserung. der Verbrennung. Es gibt viele Reglerbauarten. Die gebräuchlichsten Regler arbeiten nach folgendem Prinzip: Die im Betrieb auftretenden Druckschwankungen werdgn in elektrischen Strom, oder in Wasser-bzw. Oel-oder. Luftdruck umgewandelt. Da diese uebertragenen Schwankungen nur sehr kleine Ausmasse erreichen, werden sie zur besserer Regulierung Proportiona vergrössert und diese nunmehr absichtlich vergrösserten Schwankungen einer Regelung unterworfen. Bei Showastahlwerk sind wegen der lokalen Verhältnisse, z. B. Klima-und Arbeiterbedingungen Askania-Regler im Betrieb, bei denen Oel als Medium geberaucht wird. Diese Regler wurden in jeder Hauptrohrleitung zur Druckregulierung eingebaut und weiterhin braucht man sie fuer die Mengenregulierung und die Verhä ltnisregulierung bei der Erzeugung von Mischgas aus Gichtgas und Koksöfngas.
Neulich wurden bei den Siemens-Martin-Ofen die sogenannten kombinierten Askania-Regler eingebaut, die Ofenzug, Luftüberschuss und Gasmischungsverhalunis automatisch regulieren. In Zukunft sollen dann noch die kombinierten Askania-Regler für die Winderhitzer, Kesselund sonstigre Öfen in Anwendung kommen Wir erhoffen dadurch die Wärmewirtschaft zu verbessern und zur Steigerung der Arbeitsleistung beizutragen.

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Quick malleable cast irons which contain nickel and copper were studied in the present report. The result was as follows:
Nickel promotes the graphitization of combined carbon. Quick malleable cast irons which contain more than 2% nickel, have somewhat lower tensile and impact strength. The reason is presumed to be due to the small and flaky form of the temper carbon of nickel bearing malleable cast iron.
Copper, On the other hand, has a tendency to produce a nodular form of temper carbon. Quick malleable cast irons, alloyed with copper, have superior tensile and impact strength. The influence of copper on the annealing time was also studied.

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Mechanical tests were made on the rollings and the specimen of the low-carbon Thomas steel and open hearth furnace steel. Gas analysis as well as the ordinary analysis was performed, thus the difference in the quality of both kinds of steels being inquired. It has been thought in general that the quality of Thoams steel was inferior to that of open hearth furnace steel beeause of the former's high content of phosphorus and gases. However, according to the test result, comparison of the elongation and impact value of Thomas and open hearth furnace steel with the equal tensile strength, revealed that both kinds of steels show no substantial difference in the mean value of these properties. Besides, the phosphorus in the ordinary steel enhanced the tensile Strength and lowered the elongation and impact value, while embrittlement due to the phosphorus content scarcely occurred in the low-carbon Thomas steel. Among gases contained, nitrogen was found to improve the tensile strength remarkably, and also it was found that nitrogen plays an important role in making superior the tensile strength of Thomas steel when compared with that of the open hearth furnace steel of the same composition. Finally a summarised observation was made on Thomas and open hearth furnace steel, attaining to the conclusion that Thomas and open hearth furnace steel might be used indifferently as rollings for general structures.

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The industrically special quenching method for the 13% chormium stainless steel, which is widely used for the turbine blade in Japan, was reported. By passing a heavy current of 1, 000 to 2, 000 amps., the rolled turbine blade, due to its high electrical resistance, was raised to a high temperature which caused the metal to expand.
When the thermal deformation above the critical points Ac 1-3 reached the pre-calculated quenching temperature, the heatinge current was automatically cut-off and the quenching was simaltaneously carried out.
By means of the new process the measurement of quenching temperature with a pyrometer no longer necessary, and the aeeurate and rapid quenching always ensured. Comparing the proposed quenching method with the usual, some advantages were summarized as follows:
1) In spite of the high temperature quenching, it is free from surface decarburization and from surface scaling.
2) The product reveals an excellent finish.
3) The quenching temperature is imcomparablly accurate on account of the direct resistance heating.
4) A produet with higher mechanical properties such as greater fatigue limit and ductility, isobtained. For example:
Proof Stress Tensile Elongation Reduction Fatigue Limit
(0·2%) Strength (4) of Area ×107
As quenched 100kg/mmmm² 140kg/mmmm² 20% 55% -kg/mmmm²
As tempered 60 74 28 60 48·5
5) Thc present method is applied to the round bars, sections and tubes of common and special steels. Especially it is suitable for the thin and long sections or for the intricate profile with a uniform section.
6) The initial and maintenance costs of the present quenching appara us are very small.
7) The operation is simple and very rapia, giving a very high thermal efficiency of about 80%).
It was concluded that the new quenching method is commercially payable from the standpoint of economy and efficiency.

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The nitrogen absorption of iron was investigated by holding pure iron in contact with N₂ gas and quickly cooling it from several temperatures above 1, 400°C. The amount of nitrogen in the metal was then determined by chemical analysis. The results obtained were summarized as follows:
(1) The solubility of nitrogen abruptly decreases at the transfomation γ→δ.
(2) The temperature coefficient of solubility in the δ-iron is much larger than the value informed by Sieverts.
(3) The solubility of nitrogen in the liquid iron is the largest at the melting point of iron, that is, the temperature coefficient of solubility in the liquid iron is negative.

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The authors studied the method of determination of NH3 distilledby the apparatus shown in the previous paper. It was very difficult to titrate a very dilute sulfuric acid with n/100 NaOH.
In order to obtain a sharp end point, a number of indicators and the applieation of photometric titration were studied (Journ. Chem. Ind., Japan 38, 1934, 1924). The results of analysis of iron and steel and also the nitrogen content of reagents were shown in the Japanese text. (Cf. Institute of Techno-Analytieal Chemistry, Faculty of Engineering, Tokyo Imperial University.)

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The following method was applied for the determination of molybdenum in molybdenite and ferromolybdenum with good results.
Procedures:
(Molybdenite) 0.5g of the finely ground sample is transferred to a 200cc beaker, treated with 10-15cc of HNO₃, and heated. Then 10cc of HCl is added to dissolve the white cake. Then 30cc of the dilute H₂SO₄(1:1) is added, and evaporated into fumes of the acid.
(Ferromolybdenum) 0.5g of sample is dissolved in 20cc of the dilute H₂SO₃(1:1), and 5cc of HCl. 30cc of H₂SO₄(1:1) is added, and evaporated. into fumes of the acid,
The solution is cooled and transferred to a 250cc messflask and diluted to the mark witn water. It is then filtered through a dry filter.
A 50cc Portion of the filtrate is transferted to a Nakazono's reductor and 200g of zinc amalgam and 100cc of water are added. A current of CO₂ is passed for 2 minutes and the contents shaken for 4 minutes. The amalgam is removed and titrated with a N/10 KMnO₄ solution. (A cc)
Another 50cc portion of the filtrate is transferred to a 200cc beaker, 100cc of water added, and precipitated twice with NH₄OH to separate iron from molybdenum. The precipitlate is dissolved in a warm dilute H₂SO₄(1:10) and cooled. After being reduced with zinc amalgam as abovementioned, it is titrated with a N/10 KMnO₄ solution.
(B cc)
The percentage of molybdenqm and iron is calculated from the following formula.

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