This experiment was performed in the blast furnace plant of Kamaishi Works, Fuji Iron & Steel Co., in order to inspect whether the current sampling method of molten pig iron was adequate or, not, and then to decide the best method. In ordinary practice two samples were taken at each tap.
They were called "A" sample and "B" sample, the former was ladled on the cast-house runner and the latter was ladled at the casting machine and the grading of pig iron for sale was defined by analytical value of the "B" sample.
It was requisite to ascertain the difference of analitical value of compositions between "A" and "B" samples and the changes of molten pig compositions according to the stages of tapping, especially about Si, Mn contents.
So as to attain this purpose both "A" and "B" samples were taken from each hot metal ladle at each tap, and was sent to the test-room. The results of this experiment, obtained by several statistical methods were as follows:-
1) There was no significant difference in analytical values of Si, S and Mn contents between "A" and "B" samples, and so abolition of "B" sample must be considered.
2) There was no significant change of compositions according to the time of tapping except Si as foundry pig and S as open hearth furnace pig.
3) As for the each tap of foundry pig, Si content was observed to be low value comparatively at first, and increased gradually. During this stage Si content approached to the average value at about 3/7, and showed maximum value at about 5/7 of all stages of tapping, and then decreased again a little toward the end of tapping.
4) As for each tap of open hearth furnace pig, S content was observed to be almost constant value at first, but decreased slightly in the last 1/3 stage of the tapping.
5) That is to say, the "A" sampling of daily work was adequate for the most part, because it was taken at the third ladle among seven or eight ladles that were required one tap, however as the types of changes of Si contents of foundry pig varied somewhat each time, it was more trustworthy to take two samples at the second and fourth ladles and analyse the mixed sample of them. As to the open hearth furnace pig, it was safe for consumers to determine the S following the aforesaid sampling.

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High-sulphur free-cutting steel with specification C: 0.07-0.15%, Si<0.10%, Mn 0.80-1.20%, P 0.07% and S 0.2-0.3%, was successfully manufactured in semi-killed ingots by a 60t basic open hearth furnace aiming at high tapping temperature and short track time.
The greater part of ferro-manganese was found preferably to be added in the ladle because of stability and improvement of the yield of manganese.
There was a limit, however, of the amount of ferro-manganese to be added in the ladle from the standpoint of the ununiformity of elements and the temperature drop of the molten steel in the ladle.
Granulated pure sulphur of about 20mm size, packed in paper bags was added to the ladle. The yield of them was 62.9% in the average.
The segregations in the ingot were the same as ordinary semi-killed steel ingots and kinds and distributions of inclusions in the ingot were the same as the other examples reported in literatures of other authors on this steel.
The return scrap was to be used again as material for the steel of this sort.
Most part of its manganese ran into slag and the greater part of its sulphur into slag and atmosphere, while a small part of the latter remained in the molten bath until the end of refining period, but no trouble was found in the use of the return scrap in operation.

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The reheating furnace operation was standardized to elevate the quality and the yield. Many kinds of the test were made from the viewpoint of the combustion engineering and statistical control. The range of testing were as follows.
1. Interrelation between the thickness of scales on the ingot and the furnace atomosphere or reheating time.
2. Interrelation between the heat consumption and the furnace atomosphere or the reheating time.
3. Interrelation between the resultant effect of the steel product and the heating condition.
4. Interrelation between the separability of the scale and the furnace atomosphere or the rolling temperature.
In the consequence of these tests, the standardized operation of the reheating furnace was performed.

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To study the process of deterioration of quenching oils in long service, various sorts of fatty oil were heated at 170°C in a oil bath and blown with dry air of 10±1 1/hr/(300cc of oil) according to the Indiana Method. Then several properties of oils were determined at some interval of time.
The properties of fatty oils varied with the blowing time as follow:
(1) The quenching ability of fatty oils was rapidly lowered and given by a parabolic formula of the blowing time; This was attributed to rise of the beginning temperature of the convection stage in cooling process with lapse of blowing time. For this reason, it was possible to consider that the boiling point rose on account of the oxidation and polymerization of oils.
(2) The viscosity in logarithm linearly increased with the blowing time;
(3) The specific gravity increased and the iodine value decreased linearly with the blowing time;
(4) αC, αη, αG and αI increased parabolically with the iodine value (I₀) of oils except the peculiar oils such as castor oil, sperm oil, etc.
(5) The formation of sludge in fatty oils increased with the blowing time and was much in the order of iodine value (I₀), but was very smaller than that of mineral oils.
(6) The acid value and the saponification value increased and the flushing point lowered with the blowing time.
(7) The stability of quenching oils was determined by iodine value (I₀) of fatty oil and extremely inferior to that of mineral oils.
(8) Oils containing much of liquid wax as sperm oil was comparatively stable. Note:
t: cooling time required to cool from 700° to 350°C for oil blown with air. (sec.)
t₀: the same for fresh oil. (sec.)
η: viscosity of oil blown with air. (Redwood, sec.)
η₀: the same of fresh oil. (Redwood, sec.)
G: specific gravity of oil blown with air.
G₀: the same of fresh oil.
I: iodine value of oil blown with air.
I₀: the same of fresh oil.
τ: blowing time. (hr.)
αc, αη, αG, αI: the constant.

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Free wheels of bicycle parts were carburized by solid or liquid carburizing.
To rationalize the operation, the gas carbonitriding for the bicycle parts was studied by using the town gas alone and practised it in the plant of Shimano Industrial Co.
In carburizing, the hydrocarbon was added to the carrier gas made by cracking the town gas at 930°C. In carbonitriding the hydrocarbon and the ammonia gas were added to the carrier gas.
The composition of the carrier gas was 0.8% CO₂, 0.2% O₂ 16.1% CO, 12.7% CH₄ and 45.3% H₂.
The results obtained were summarized as follows:
1) The carburizing temperature was 900°C and the holding time at the temperature was 1.5hr. The added hydrocarbon was 2.5cc/min and the flow of the carrier was 50L/min. The carburized layer 0.7mm thick was obtained and the hardness of the work was HRc 59 after a direct oil quenching.
2) The carbonitriding temperature was 820°C and the holding time at the temperature was 2 hours. Added hydrocarbon was 1.5cc./min and the ammonia gas was added 7L/min. The carburized layer 0.4mm thick and the compound layer 0.15mm thick were obtained. The hardness of the work was HRa 81 after a direct oil quenching.

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The dimensional change of standard specimens, A type and B type, made of carbon tool steel, high C-Cr-Mn-W steel and high speed steel, was studied after conventional heat treatments and besides after interrupted quenching, the so-called martempering, marquenching and time quenching. A large portion of dimensional changes on quenching possibly was attributed to the thermal stress during the rapid cooling. By martempering, the high thermal strains were eliminated excepting those unavoidable strains in the piece resulting directly from the austenite to martensite transformation. As the result of this experiments, marternpering was found suitable for the heat treatment of high C-Cr-Mn-W steel and high speed steel, especialy in A type specimens whose shape was so complicated that the dimensional change on quenching was not diminished by subsequent tempering.

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When carbon steel wire rods were treated by the electrolytic method which was usually employed for the determination of nonmetallic inclusions in iron and steel, following facts were found concerning the produced black residues.
(1) The quantities of the produced black residues were found larger in case of the electrolysis method than in case of the sulfuric acid method.
(2) When the current density was lowered by increasing the number of the rods at a constant voltage, the amounts of the black residues were increased.
(3) About the elements contained in the electrolytic residues, the results were as follows. The suffix 1 and 2 indicated the electrolysis method and sulfuric acid method respectively.
(a) C₁>C₂ (b) Si₁<Si₂ (c) Mn₁<Mn₂ (d) P₁>P₂ in case of Japanese products and P₁_??_P₂ in case of foreign products. (e) S₁>S₂ (f) Ni₁<Ni₂ (g) Cr₁>Cr₂ (=0) (h) Cu₁=Cu₂, in both cases, Cu was all remained undissolved. (i) Fe₁>Fe₂, the value of Fe₁ was specially high in case of Japanese products. (g) H₂O₁<H₂O₂ in case of Japanese products and H₂O₁>H₂O₂ in case of foreign products. (weight decrease)₁>(weight decrease)₂.

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1. In early days of automobile manufacture, in Japan, U.S.A. and England, high alloy steels were used to make automobile parts. But afterwards, developments of design of automobile parts, to-gether with more accurate manufacture and finer surface finish, have greatly improved the service life of automobile parts.
This resulted in very much less accent on the importance of basic alloy composition, so that the available lower cost, lower alloy grades could, with the highly developed heat-treating control and investigation on the hardenability of steels, be used interchangeably for automotive applications.
2. The author investigated and compared the grades of steels made in Japan, U.S.A. and England, concerning not only the kind of steels but also a quantity of incidental alloying elements, non-metallic inclusions and the grain size in steel.
The result of comparison showed that, grade of automotive steels made in U.S.A was the best of all and steels made in Japan was, to a great regret, the poorest of all.

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