After the desulphurizing reactions between the liquid pig iron of Fe-C-S system and the solid lime and calcium carbide were discussed in accordance with the phase rule, the relation between the equilibrium values of the carbon and sulphur contents of the iron and temperature was calculated with thermodynamical data. The limit of desulphurization with the solid lime was very low and it decreased with the increase of the carbon content of the iron when temperature and the partial pressure of carbon monoxide in gaseous phase were constant. The limit of desulphurization with solid calcium carbide was also considerably low and it decreased as t content of the iron decreased at a given temperature.
According to the equilibrium data of the reaction CaO(s)+3C=CaC₂(s)+CO(g) desulphurization of the pig iron with solid lime was generally larger than with carbide and its minimum value was equal to the limit of desulphurization with carbide.

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Sampling molten slag with a spoon out of the furnace at several stages of O-H steel refining operation and casting it into a mild steel plate mould, with a diameter of about 75mm and a height of about 10mm, the author examined the relation between the surface texture (top, bot tom and fracture) and the components of slag.
The results showed that surface texture of slag pancake could be classified into fiive groups (I. creased, II. intermediate, III. furrowed, IV. spider web, V. concave or flat) according with its basicity. And it was found that in each group, surface texture differed according to the differences in basicity and other components. Consequently it was confirmed that if a standard sample was prepared in advance, components of non-determined sample conld be presumed by comparing with it and its basicity could be estimated with an error of 0.1 or 0.2-0.3 respectively at under or above 2.5 V_p(=CaO/SiO₂+P₂O₅). Estimation of FeO, MnO and P₂O₅ was also possible to some extent. The time required in the estimation being within 2-3 minutes and an intricate apparatus or skill being not particularly required, so this method is at present regarded as the most proper one for slag control in O-H operation.

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It has been recognized so far that titanium easily combines with nitrogen and carbon to form titanium-compounds, but there is another important relation between titanium and sulphur. Therefore, the author studied the general relationship between these elements, carbon, nitrogen, sulphur and titanium, when such elements co-exist in steel, as well as some experiments were performed on varions properties of titaninm-sulphide. Results of these tests were summarlized as follows:-
1. When these elements, carbon, nitrogen and sulphur, which ba strong chemical affinity for titanium were contained in steel with titanium, it was found that nitrogen in steel preferentially combined with titanium to form titanium-nitride, and secondly sulphur and carbon combined with titanium to form TiS and TiC in this order. It was considered that the chemical affinity between titanium and such elements was in the following order, i.e. nitrogen, sulphur and carbon.
2. The effect to reduce the sensibility in sulphur print was based on the stable charactor of TiS agamst acid. When TiS in steel was increased and FeS and MnS in steel was decreased, gradually the denseness of sulphur print decreased. When all sulphur in steel comhined to form TiS and there was left no FeS and MnS in steel, the arthor could not obtain the sulphur print of this steel. From the analytical results it was found that, when titanium content in steel was about as much as of sulphur, all sulphur in steel combined to form TiS and there was little sensibility for the sulphur print in this steel.
3. TiS was present in steel in the state of microscopically small particles which had light violetgray colour, and it was discriminated clearly from fine particle TiC. TiS was not fluidtically deformed by hot working, but separated to fine particles and produced the lamination structure in steel.
4. TiC could be soluble in γ at temperature above 1000°C and its solubility increased accordingly as temperature rose. But if these were large quantity of TiS with TiC in steel, the solubility and the precipitation of TiC decreased. It was considered that TiS in steel had such charactor as to obstruct the solution and the precipitation of TiC.
5. TiS had remarkable effect to prevent the hot shortness by sulphur in steel. Hence titanium may be used as substitutional element for manganese.

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In order to utilize Ni-Ti steel for materials of the ammonia synthesis equipment the author studied various effects of titanium on low carbon-3% nikel steel. Percentage of added titanium was in the extent of 0-1.0%, and the authors especially investigated in detail for the range of slight additions. Results of these tests were summarized as follows:-
1) In manufacturing of titanium steel, yield of titanium was improved according with increase of additional titanium quantity.
2) Denitriding effect of titanium on Ni steel was very effective even if the quantity was slight.
3) By addition of titanium to Ni steel, the macrostructure was changed to the small and uniform dendritic structure.
4) Both the A₁ and A₃ transformation points of Ni steel rose with increase of the titanium content.
5) When titanium bearing steel was quenched from high temperature as its carbide was dissoved, it was greatly hardened and caused brittleness. Then there occurved precipitation hardening by tempering at about 550°C and it seemed that hardening was maximum in 0.6% titanium.
6) in normalized condition at 900°C, the tensile strength slightly decreased, and elongation and reduction of area slightly increasd the with titanium content. Shock resistance was greatly improved according with the increase of titanium content, but it seemed that the most suitable titanium percentaee which improve its toughness is about 0.3-0.4%.
7) In microstructure, it was recognized that the cementite in steel gradually disappeared and fine titanium carbide appeared with increase of the additional titanium percentage.
As for grain size, titanium content under 0.3% was effective and more titanium addition resulted in a marked coarse grain mixture.
8) Non-metallic inclusion remarkably increased with titanium addition.
9) From the result of attack test on the Claude catalytic tube, it seemed that the effect of titanium, addition appeared for the first time when it was added in steel in quantity more than to fix all the carbon in steel to titanium carbide, and a deficiency of titanium caused cruck.
In Ni-Ti steel which fixed all the carbon in steel, an etching ring of high hardness appeared on the surface zone by absorption of nitrogen gas, but the quantity of the absorbed gas was little and it became almost constant.

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White cast iron specimens of ordinary malleable cast iron grade were heated for short time repeatedly at comparatively lower or higher temperatures, and these mechanical properties and structural changes were studied.
Followings were the principal results obtained.
1. Repeated heatings seemed to promote the softening of irons as compared with the case by single heating.
2. At comparatively lower heating temperature as 870°C, the cementite scattered in globular forms with a little amount of decomposed temper carbon, and the iron had a tendency to become the-so called high strength pearlitic malleable cast iron.
3. The iron became the tougher as the heating temperature rose higher, showing the increasing of temper carbon instead of a globular cementite.
4. By repeated heatings even if it was at unusual high temperature e.g. at 1050°C, the tendency to become a coarse flaky graphitical decomposition such as was seen by single heating was much reduced.
5. Rapid heating such as was in salt bath, facilitated the softening of iron and a tougher and stronger iron might be expected as against by slower heating.

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A contamination which occurs during the process of grinding coke as a result of abrasion of the grinding due to the hardness of coke in property is fairly well known, but despite this, no satisfactory and rapid method has been recommended for practical use up to now. Monthly average result of Fe₂O₃ in the ash of lump coke was higher by about three percent than in the ash of coal charged into coke-ovens. After the authors made several investigations, they found that iron came into the sample as a contamination from the crushing apparatus by hard motion of grinding.
The authors reached the conclusion that the use of an agate-mortar was the most ideal method, but was not suitable for daily practice as the process took long time. At the authors works, the sample obtained was crushed on "backing board". The use of magnet for the removal of such contamination was almost satisfactory but needed a troublesome procedure and wasted part of the sample.
Therefore, grinding of coke by a pounding method gave the minimum error and was found to to be the most recommendable.

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Nowaday, some kinds of oil, resins and corn flours et al. are used as core sand binders to obtain desired properties of the core. But these core have weak strength in green sand state.
The authers have studied how to strengthen the green sand as well as the baked sand and to improve the permeability.
The results were as follows:
1. The strength of the baked sand in compression and bond test was excellent when dextlin, linseed oil and novolack were added each alone to the sand. The strength of green sand was greatly improved by adding rubber chloride, dextlin and novolack.
In the case that two or more kinds of binders were mixed with the sand, high strentgh was obtained when novolack, resin or dextlin was added in combination with 4% of linseed oil, and excellent strength was obtained when 2% of linseed oil, 2% of novolack, 1% of resin and 1% of dextlin were added to the sand.
2. Permeability of the baked sand has opposite inclination to the strength. Resin, vernish, pitch and novolack decreased the permeability of the sand in this order, but those values of permeability showed good results when baked at 200-250°C.
The addition of two or more kinds of binders decreased permeability not so greatly. Compression strain was maximum at the baking temperature of 200-250°C.

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Description was made on the development of the Wiberg-Söderfors process, and the existing plant at Söderfors, Sweden. Different reducing agents, requirements demanded of the ores and the economic efficiency were mentioned, with reference to uses of the sponge iron and the future plan concerned.

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