The specimens of manganese iron which contains up to 3.82% of manganese are made by the melted iron obtained from the sponge iron by hydrogen reduction with the metallic manganese in the market. Ten ingots of different manganese content are forged into the proper shape for the investigation. The measurement of electric conductivity, the mechanical testing and the microscopic investigation on the specimens were carried on as forged, annealed and quenched conditions.
The electric resistivity of the annealed sample increases 0.6 microhm by incrensing 0.1% of Mn and that of the quenched sample is little higher than annealed ones The tensile strength and the elastic limit gradually increase up to 2% Mn, proportionally to the manganese content and over 2%, the ratio of increase is remarkable. In the quenched sample, these increase is marked up to 2% Mn, over 2%, the rate of increase in tensile strength is reduced and the elastic limit decreases suddenly. The elongation and the reduction area decrease exceedingly up to 0.2% Mn, over 0.2% they do not show much decrease by increasing the manganese content and over 2.2% Mn show sudden decrease. In the quenched specimens the rapid decrease of the reduction area is recognized increasing manganese under 0.67% and by increasing more manganese there is not much change in elongation and reduction area. But there is shown sudden decrease from 2.8% to 3.8% Mn in which malleability can hardly be recognized.
The impact value is markedly reduced as the manganese content decreases. Especially in the annealed condition, this phenomenon is more marked, in 0.7% Mn it is 3kg. -meter. Then as the manganese content increases it suddenly goes up and reaches maximum, 13kg. -meter, in 2% Mn. Over this content of manganese it shows sudden decrease and in 3.8% there is almost no value in all conditions.
In the micro-scopic investigation, the structure of low manganese specimens in annealed condition consist all ferrite crystals. When the manganese content increases to about 2% some martensitic structure appears and in 3.8% manganese it changes completely to martensite. In the quenched condition, the martensitic structure appears already in 0.677% manganese and the structure becomes completely martensite in 2% manganese.

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In the first part he studied the relation between the chemical composition, structure and the corrosion of ordinary cast iron. The corrosion tests were carefully carried out in a specially designed apparatus and reliable results were obtained as compared with the preceding investigations.
Si increases the corrosion in dil. HCl to 1.6% of its content and then decreases while in dil. HNO₃ & tap water garadually decreases to 2% Si.
Prapidly raises the corrosion rate in dil. HCl to 1% P but slightly lowers Sn dil. HNO₃ & tap water.
Mn, in dil. HCl, for pearlitic cast iron (low C. low Si) the corrosion rate has minimum at about 0.8%Mn, while for high C, high Si cast iron(containing free ferrite) the corrosion rate reaches maximum at about 1% Mn. In dil. HNO₃ Mn decreases the corrosion for the both kinds of cast iron to about 1% Mn and slightly decreases in tap water.

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The experimental works were undertaken by the au her, dealt with phenomena of pitting and passivity upon specimens, Cast Iron, Armco Iron, Eutectoid Carbon Steel and Copper Bearing Steel, which were immersed both into artificial and natural water.
Using special measuring methods of potential under reference of O₂ content in the water and heterogenousness of materials considering Ph value, electrolyte and current density.
Another method was used for researching of O₂ and CO₂ as a factor on pitting and passivity under moving aerated water.
Results were discussed and recognized as follows, viz.:-
1) Passivity of Iron and Steel in water is the formation of oxide film by direct oxidation.
2) Pitting is a result of the nonuniformity of passivity on the whole surface of the specimen.
3) Main causes for the lack of uniformity of passivity are two, viz.: One is the depolarisation of the passive part by the hydrogen generation, and the other is the partial passive state formation by the differential aeration.
4) Current sets up between the surface, which is protected by an oxide film as a cathod, and the other parts as an anode. With reference to current flow, special calcium magnesium silicate scales were deposited only on the cathodic area in the natural water.
5) The order of the initial pitting tendency of the specimens are copper bearing steel, armco iron, eutectoid carbon steel and cast iron, and these results are on account of the direct oxidation of the material by oxygen.

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In this expriment author used various type of commercial electrodes and special made electrodes which were added Silicon, Aluminum, Phosphorus and Manganese in the coating material. The deposited metal from these electrodes were tested to find the electromagnetic property, mechanical property and change of these properties before and after aging and annealing. The results of this investigat on are as follow:
1. The electric resistivity of the deposited metal from the low carbon bare electrode was comparatively small. Therefore it is suitable to weld the electric circuit. But the mechanical quality of the weld metal deposited from the bare electrode was inferior to that deposited from the covered electrode.
2. In the case of the magnetic circuit welding the deposited metal must have high permeability, low hysteresis loss and high electric resistivity. For these purpose it was applicable to use the electrodes that were coated with the proper quantity of silicon and manganese. However manganese itself is not directly to afford the good effects to the magnetic property of the deposited metal but it reduces the contamination of air to the deposited metal.
3. The deposited metal from the phosphorus coated electrode was a little better than that from the bare electrode. It was, however, so brittle that was readly cracked by light hammering. The iron aluminum alloys were similarly to the iron phosphorus alloys except under the critical quantity of aluminum.
4. The deposited metal in arc welding possessed in general the conspicu us aging property. However it was so much improved that hysteresis loss increased with time as little as neglible if the electrode had coated with silicon and manganese.
5. The magnetic characteristcs of the deposited metal were much affected by the cooling rate of the metal, especilly. below 500°C.
6. The deposited metal from the manganese coated electrode developed the high tensile strength and that from the silicon coated electrode developed the high impact resistance. The deposited metal from the covered electrode with silicon and manganese had the superior mechanical properties.
7. Author indicated the microstructure of deposited metals from the various type of the coated electrode. In the presence of silicon, the grainsize was large. But if the manganese had been added to the electrode, grain-size of the deposited metal was fine. Up to the quantity of phosphorus reached 0.5% in deposited metal, author found the characteristic sharp needle structure in it.
8. The welded metal of the low carbon steel by the atomic hydrogen welding process possessed the good electromagnetic and mechanical properties. But it had a considerable aging effect in magnetic characteristics.
9. The silicon coated eletrode was practically impossible to be deposited by the electric are process on account of the large grobule of the electrode dropped down. However the silicon and manganese coated electrode was possible to obtain the deposited metal with some difficulties.

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