In this investigation granulated eutectic cuprophosphorus was examined for the purpose of grain refinement of the primary silicon crystals in the hypereutectic Al-Si alloy containing about 24%Si.
  With an addition of less than 0.05%P, incubation (retardation) period of refinement can be observed in the hypereutectic Al-Si alloy. However, primary silicon crystals were fairly refined with an addition of over 0.1%P without isothermal holding of the molten alloy. Because of the lower melting point, the eutectic cuprophosphorus gave more satisfactory results than 15%P-Cu alloy in reducing the incubation period of the grain refinement. Judging from the results of the chemical analysis, distribution of residual phosphorus depends upon the copper diffused in the molten alloy, where distribution and gravity segregation of copper promote the concentration gradient of the residual phosphorus; subsequently the incubation of refinement seems to originate in the diffusion of copper in the molten alloy.
  The residual phosphorus content in the alloy sufficient to the grain refinement of the primary silicon crystals was 0.0055%. However, the additional phosphorus content should be required over 0.1% considering the tensile strength of the alloy.

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  The effect of coke ratio on molten iron temperature at constant blast volume has been studied and some investigations on the difference between the curves of Jungbluth and Piwowarsky have been made.
  Midget cupola (I. D. 200 mm) has been operated with various coke ratio and the temperature change of molten iron in the well has been measured throughout the operation.
  The experimental results were as following :
  1) The higher the coke ratio is, the higher becomes the temperature of molten iron in the well.
  2) While the molten iron is stored in the well its temperature drops by heat losses.
  3) The longer the storing time is, the more decreases the iron temperature.
  4) The temperature of iron in the well is higher at the upper layer and lower at the bottom.
  5) When the coke ratio is high, the melting rate becomes low, therefore the time to store the equal quantity of iron becomes longer; consequently the temperature decreases more.
  6) Because the so-called tapping temperature is affected by the temperature decrease mentioned above, it is complicated to note it as it differs by the time or the position of its measurement.

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  Although outward appearence and manual inspection were empirically the sole creteria for comparing foundry cokes, it is necessary to perform the chemical, physical and engineering tests indicating actual differences in thermal and metallugical behavior in the cupola. Many publications have described on the tests of foundry coke. Among various properties, size, ash content and porosity of coke are considered by many foundrymen to bear important relations to combustion characteristics in cupola. On the combustibility and reactivity, however, no distinct result and consideration were obtained. Consequently, it is rather difficult to anticipate the actual combustion behavior of coke in the melting or oxidizing zones of cupola.
  With the view of finding some relations between experimental works on coke and the combustion characteristics in cupola used in foundry, and experimental water cooled cupola with no lining was constructed in the authors' laboratory. The humidity control of blast air was obtained by absorption method. This cupola consists of five zones, i.e., well zone, combustion zone, reactive zone and two intermidiate zones for gas trap. Its shell has the internal diameter of 216mm surounding by steel plate of 15mm and heat resistant steel of 10mm thickness. Various foundry cokes were charged both in the lower combustion zone with water cooled jacket and in the reactive zone heated by electric resistance furnace installing with resistance wire and rod. With the view of inspecting and measuring temperature, this cupola has three holes at three different levels. Foundry cokes having ash content ranging from 4.9 to 8.8pct and porosity ranging 30.8. to 44.3pct were charged in the combustion chamber for investigating combustion behavior in the furnace. During the combustion of each coke in the cupola, temperature at three levels of the furnace, carbon dioxide content of gases from both combustion and reactive zone, temperature of water from jacket, consumption of coke, blast pressure and air volume etc. were investigated.
  Besides these experiments the combustion behavior of the same series of coke were observed in a thermo balance. The weight decrease of the cubic coke specimen having a weight of 2grams was recorded automatically with the furnace temperature on slow heating. Also the weight loss of coke holding at constant temperature for 10 and 20minutes was measured.
  The results obtained were as followinges:
  1. Because of jumping and floating of the coke specimen in combustion zone when blasted by air volume as 3.9 to 4.5m³/min that is proportional to the normal blast volume using in commercial cupola, the air volume under 3.0m³/min only was used in this experimental cupola. This caused to obtain the maximum temperatures differed from that observed in the optimum condition of the combustion in cupola.
  2. It has been concluded that the temperature of hot water came out from water jacket is seemed to be an indicater of the average furnace temperature.
  3. Some results showed the fact that there is a close relation between the consumption of coke and porosity. The consumption of coke increases with its porosity. Moreover, thermal test in thermo balance proved this fact.
  4. The reactivity of these cokes was seemed to increase with their porosity values.
  5. On the ignition temperature of coke, there seemed to have a close relation with porosity ash content.
  6. In the authors' laboratory, consequently, as no distinct difference especially as ash content and porosity were obtained, they wish to investigate in near future the combustion behavior in cupola by using the series of coke with constant ash and varying porosity, or constant porosity and varying ash content.
  It has been clarified that the coke test as above mentioned in thermo balance indicate the approximate thermal behavior as in cupola.

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  In producing nodular cast iron, it is desirable that the nodulant has both properties of powerful spheroidization as Mg and mild reaction as Ce. Authors studied whether Y had such properties or not as a nodulant and several Fe-C-Si ternary alloys were prepared for the investigation. These alloys with various contents of Y were melted in Criptol electric furnace and the degree of spheroidizing were examined. Besides the cooling curves of the sand cast specimens containing Y melted in tamman tube were gotten and discussed.
  The results obtained were as follows
  1) Y has the spheroidizing power of graphite.
  2) Reactivity on addition is rather mild.
  3) To get the spheroidal graphite residual content of Y in iron should be more than 0.15%.
  4) Residual S content for producing Y nodular cast iron is less than 0.02%.
  5) Y addition gives no influence to Si, Mn and P content in the iron it is accompanied by decarburization and desuluphurization.
  6) Y promotes the super-cooling of the alloy. The primary precipitation point of graphite of the hypereutectic cast iron is lowered. Cooling curve of a eutectic reaction showed complex double changes.
  7) Inoculation by Fe-Si after Y addition decreased the super-cooling of the alloy.
  8) Chill formation is rather strong by Y addition.

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  The author has studied on the induction hardening of various cast irons such as grey cast iron, black heart malleable iron, and spheroidal graphite cast iron for these several years. In these studies, the results obtained were as follows; meehanite iron and spheroidal graphite iron have good hardenability and have a sound surface without cracks. The studies on induction hardening of spheroidal graphite iron have been reported by many authors. Recently the high grade cast irons which are manufactured in small foundries in this country are inoculated cast iron, and meehanite cast iron is also an inoculated one. Generally, the inoculated cast iron could be case hardened successfully as mentioned above, so the author has studied further on the hardenability of some inoculated cast irons.
  In this report, he has carried out the study on the hardenability and soundness of hardened surface of inoculated cast irons which were treated by various amount of inoculant Ca-Si.
  The following results were obtained.
  1) Hardenability of inoculated iron was less superior to untreated iron.
  2) Hardened surface of inoculated iron was comparatively sound.

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  The features of wear mechanism of cast iron under the state of lubricating, sliding are as follows.
  1) Oxidation of frictional face owing to the oxygen absorbed in the lubricating oil.
  2) Oil absorption of graphites on contact faces, which influences on wear.
  In this study these phenomena were investigated, and from the results, lubricating, sliding wear mechanisms of cast iron were discussed. These were summarized as follows;
  1) The change of character accompanied by the oxidation of the lubricating oil was investigated. It was to be noted that viscocity, viscocity index, strength of oil film which had direct influence on wear became worse, as lubricating oil was more oxidized.
  2) When the experiment was made on the lubricaring oil which was in some degree oxidized, the frictional surface was oxidized by the oxygen absorbed in the oil. The oxidized frictional dace improved protective character of oil film. Accordingly, wear loss in this state was inclined to decrease. But when remarkably oxidizing oil was used, it was difficult to supply the oil to the gap of contact face on account of lowering the strength of oil film and increasing the viscocity accompanied by oxidation, so it was found that wear loss increased rapidly owing to adhesion.
  3) The influence of the spaces between graphites on the contact surface on wear was examined. It was found that in a range in which mechanical wear took place mainly, the wear resistance of initial and continious wear improves as mean value of graphites' space decreases.

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