In view of utilizing domestic resources for the iron manufacturing at Wanishi Iron Works, its blast furnace operation has desisted from the use of strong caking foreign coal and is now carried on with coke made entirely from Hokkaido coal. The operating blast furnaces at present are two sets, namely the Nakamachi No. 3 B.F. (nominal capacity 700ton/day output) and the Wanishimachi No. 3 B.F. (nom. cap. 225ton/day). The Nakamachi B.F. is operated with the coalite coke, while the Wanishimachi B.F. mainly with coke made from Hokkaido coal without blending of coalite.
As the Hokkaido coal is highly volatile, the ordinary coke made therefrom is weak and brittle. The coalite coke, made from the same coal blended with 25% of pulverized coalite, has 16% ash and Strength by Drum Test as much as 80%, which, however, is not yet strong enough for the large 700ton furnace. Our effort in devising better ore preparation and appropriate operation methods to supplement the deficient coke strength has thus far made it possible to produce about 600tons of pig iron per day.
The Hokkaido coal-made coke not through blending of coalite has 17% ash and Strength 50-60%. The Wanishimachi B.F, capable of effectively using such less strong coke or under-size coke, is qualified to produce pig for outside sale. In the present situation, when obtaining of strong caking coal is difficult and the production capacity of coalite still insufficient, the small blast furnace is doing an important part in this industry.

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Using the results of the previous report, calculated the eqiuilibrium constant of the reaction and obtained the equation
Here, ( ) indicates the mol fraction of each free component in the slag and[ ] the weight % in iron. The, calculated the equilibrium constant of the reaction and obtained the equation

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To improve the combustion effect in the open hearth furnace heated by the producer gas, the velocity of the combustion of the gas must be accelerated, and this acceleration is to be brought by the acceleration of the velocity of the mixing of gas and air, As this means, a method to blow compressed air gas port from both sides of the port through a water cooled pipe was tried in the first report.
In this second report, a air jet type gas port which can blow primary compressed air into the gas port and gives the effect of explosion, combustion, just as like a Bunsen burner, was examined. By this improved method, good results as follows, as comoared with the former method was obtained. That is:-
1) As the mixing rate of gas and air is much acceralated, the velocity of combusion is increased, and so, short and sharp flame is obtained.
2) The melting time is reduced by 20%
3) The fuel is saved by 15% during the melting time.
4) The flame direction and speed is easily controlled by the controlling of the pressure of compressed air.

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The analysis of the piercing mechanism of Mannesmann type piercing machine-the most important application of the oblique rolling-was projected from various experiments.
This report contains the results of experiments on the axial slip between main rolls-oblique rolls and rolled billet and on the power consumption in piercing. The results obtained are as follows:
1. The axial slip is higher than the case of ordinary rolling.
2. Power consumption per ton of pierced billet A/W (KWH/ton) is proportional to the deformation degree of piercing φrm, i.d.
3. Ideal piercing work is nearly 15% of real piercing power consumption of the driving motor.

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Quenched Sweden carbon steels containing about 0.1, 0.3, 0.5, 0.7, 0.9, 1.2 and 1.3% C were subjected to repeated heating and cooling passing A1 point, and the effect of carbon content on the spheroidizing of cementite in those steels was studied.
One cycle of heating and cooling was carried out as follows:
700°→760°, heating 1°/min., hold at 760° for 14min.
760°→700°, cooling 1°/min., hold at 700° for 30min.
This cycle was repeated 1 to 5 times, and after each cycle the rate of spheroidizing of cementite was measured by means of Rockwell hardness tester.
After 3 times of the cycle in Hypo-eutectoid steel and after 5 times of it in Hyper-eutectoid steel the spheroidizing was completed - that is, the lowest constant hardness was obtained.
Difference of the quenched structure - if the same steel - does no effect on the final spheroidal structure and its hardness by this heat treatment.
The final hardness of spheroidized steel thus obtained is expressed by following formula:
Rockwell hardness in B scale =21×C%+72.9
This hardness is more or less higher than that of the spheroidized one made from the same steel having the lamellar pearlite structure.

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The isothermal transformation curve (T-T-T Curve) of a standard hot work tool steel was determined by dilatometric, hardness and metallographic tests in the range 810 to 400°C. The curve discloses that the austenite of this steel transforms very slowly between 600 and 460°C when quenched from the austenizing temperature of 1200°C. The rate of transformation is fastest at about 775°C. The supercooled austenite of this steel is transformed to martensite and converted to an acicular product when cooled just below 400°C.

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For the determination of hydrogen in the cast iron, vacuum extraction method of the steel is studied, and gained the following results.
1. The test piece of 15mmφ are in cast in the copper mould and quenched rapidly in the Hg bath. By this method, the test piece are white pig iron, and no quenching crack are seen.
2. Extraction temperature of hydrogen should be 900°C.
3. Hydrogen in the cast iron do not escape from the piece at room temperature. So that analysis is not necessary to carry out as soon as the test piece is cast.
4. The results of the analysis are reliable, and will be useful for the determination of hydrogen in the cast iron. By the procedure above described, analysis were carried out in the some cast iron, and we gained the following results.
1. Hydrogen in the cupola melt cast iron is smaller than that of the electric furnace melt cast iron.
2. Si content of the cast iron effect the analysis value and hydrogen in the high Si cast iron is smaller than that of the low Si cast iron.
As the conclusion, this procedure is not absolute one for the analysis of hydrogen, but for the cast iron of the about same composition, the comparative valve will be gained, and be useful for the investigation of the graphite structure in the cast iron.

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The rapid metbod for determining phosphorus in iron and steel by centrifugal method developed formerly by one of the authors was applied to rapid determination of phosphorus in ferromanganese, and satisfactory results were obtained in about ten minutes. The procedure is as follows: After transferring 0.1 gram of sample to a 100cc conical or egg-plant shaped flrask, dissolving it in about 10cc of HNO₃ (1:1) (or 5cc of conc. HNO₃ when sample is not finer than 100 mesh), and boiling to expel oxides of nitrogen, filter the solution. Then washing with a little quantity of water, oxidizing by adding KMnO₄ (2%), boil it to form brown pricipitate of hydrated manganese dioxide. Dissolving the precipitate by adding one or two drops of H₂O₂, saturated oxalic acid solution or FeSO₄ (5%), boil it. After adding 20cc of molybdate reagent, stoppering the flask, and shaking it vigorously for 1 minute, transfer to special small centrifuge tube with P % graduation on its capillary without washing. The volume of the solution should now be about 30cc. After centrifuging at 2000r.p.m. for 1 minute, removing the tube from the machine, read the percentage of phosphorus directly. on the capillary.

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This report contains the outline of the items decided at the third, fourth and fifth general meetings and the first and second special committees and those which are now on the way of investigation.
The main items decided at the Ingot Mould Investigation Committee are as follows:
(1) Unified classification of the causes of disusing ingot mould. (2) Hysteresis table of ingot mould. (3) Heat treatment of ingot mould. (4) The method of using ingot mould. (5) The method of sampling from ingot mould for microscopic test. (6) Research on the results of using ingot mould at each steel manufacturing factory. (7) The relation between pig iron as the raw material and the life of ingot mould.
The items decided at the Roll Investigation Committee are as follows:
(1) Selection of Shore Hardness tester. (2) The influence of combined carbon on the hardness of chilled roll. (3) Operation of reverberatory furnace for melting chilled roll. (4) Special properties of grain roll and the results of using it. (5) Research on the results of using roll at each steel manufacturing factory.

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