The New Caledonian iron ore which has been shipped to the Nippon Kokan K.K. (Japan Steel Tube Mfg. Co., Ltd.) for charging into a blast furnace contains 0·2-0·3% Ni and 2·5-3·0% Cr. However, when it is used as part of the charge to the blast furnace, the greater part of the nickel and chromium is diluted so that it is impossible to use it for special purposes. On the contrary, when the ore is smelted independently in an electric furnace, part or much of the nickel and chromium remain in the pig. In order to utilize such kind of pig, impurities such as phosphorus and sulphur should be restricted to a certain limit and the carbon is required to be less to some degree. In view of these points, a preliminary experiment was conducted in a 1.5-ton small electric furnace, following which an industrial scale experiment was later made with a 20-ton large furnace obtaining the pig of the following composition:
The former composition may be applied in alloying to special cast iron and the latter is the most suitable for the material of special steels.

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In Japan, the temperature measurement of liquid steel is generally made with the aid of an disappearing-filament optical pyrometer. Since the beginning of 1935, the 19th Sectional Committee of the Japan Society for the Promotion of Scientific Research have endeavoured to establish the manner of calibration and to study the suitable method of measurement with an optical pyrometer. A standard electric lamp has been developed, with which acting observers of several steel works were assembled many times to measure the temperature of liquid steel simultaneously. After a long discussion, the value of emmissivity was tentatively determined to be 0·45 in the usual case of the steel casting period under tundishes or ladles. In the present paper, the means for measuring the temperature of liquid steel, was fully explained, the emmissivity value being taken as 0·45.

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Following the first report (Tetu to Hagane, Vol. 23 (1937) p.787), the present paper dealt mainly with the effect of the forging ratio on the hardness at ordinary and high temperatures, the microstructure and the cutting efficiency of high speed steel tools. The author then gave a theoretical explanation of temper hardening phenomenon in the quenched and tempered high speed steels (especially, at different tempering temperatures between 500-600°C), by means of hardness test, thermal expansion test and microseopic test.
Moreover, the author studied the effect of the two different methods of producing sintered tungsten carbide series tools. One method is the direct production from the powder by using a self-recording compression tester attached to the specially devised apparatus which has been described in the first report. Another method is to prepare the tool by sintering after pressing the powder at ordinary temperature by using the specially devised apparatus. Finally, the author studied the effect of the grain size of the powder on the sintered carbide tool.

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It is generally required in the plain WC-Co system hard alloys that the fracture, i.e. the grain size should be refined. The grain size has a remarkable influence on the impact value and wear resistance just as in the other metals. The effect is most prominent in the efficiency of cutting tools and other parts which meet both impact and wear. The author investigated into the relation of the cutting efficiency with the hardness, porosity and microstructure (especially, the grain size of carbide) of the plain tungsten carbide hard alloys with 6%Co.

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