It was difficult to catch experimentally the remelt phenomena in the initial freezing zone on the surface of a rod steel, which was wrapped with molten cast iron, as this phenomena was accomplished in a very short period of time.
  Therefore, the authors applied the graphical method to reveal the change of temperature distributions after pouring the cast iron in camlachie cramp.
  The latent heat was considered at the use of graphical method.
  It was concluded that in order to determine the limit of the meld in camlachie cramp, not only the volume ratio of steel to cast iron, but the ratio of volume to the surface area of the steel, which was wrapped with molten cast iron, must be considered.

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  The structure of grey iron as well as the graphitization of white iron effected by the melting atmospheres were investigated. Synthetic irons of Fe-C-Si-P alloy system with hypo, hyper and just the eutectic compositions of carbon were melted in vacua, then they kept melting in the flow of the mixed gasses such as nitrogen, hydrogen and carbon monoxide with argon respectively. The surrounding atmospheres of the molten irons were controlled by changing the mixing ratios of the gasses to argon. The graphite structure melted in vacuum was undercooled but it coarsened progressively to flaky when the atmosphere contained nitrogen or hydrogen. The coarsening of graphite was remarkable in the irons of hypo or hyper eutectic compositions depends upon the atmosphere containing nitrogen or hydrogen respectively.
  Generally, in hypo eutectic alloy, the graphites once coarsened and then refined by increasing the partial pressures of nitrogen and hydrogen of the melting atmosphere, which seemed to be attributed by the segregation of gasses in the eutectic liquid owing to the separation of primary dendrites of austenite.
  It is suggested that the segregation of gasses has responsible to the eutectic solidification as the flake graphite was formed at the boundaries of the eutectic cells preferably but proceeded inwardly in the cells by increasing the gas contents.
  When the atmosphere contained carbon monoxide, the oxygen in the molten iron increased proportionally by the partial pressure of the gas but not so much change in the graphite structures, while ledeburite tended to form with refined dendrites of primary austenite in hypo eutectic alloy.
  Small addition of sulphur coarsened remarkably the structure of graphite in grey iron and promoted the graphitization of white irons.
  Then, the synthetic irons of Fe-C-Si system were melted in various atmospheres as before and sucked up in a silica tube to freeze as white, and the graphitization of which was investigated by dilatometric method annealed in argon atmosphere. It was found that both nitrogen and oxygen retard the first stage graphitization and the former was effective at higher partial pressure but the latter at lower one.

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  The authors made an investigation on the heat resisting properties of castings for high temperature service, which are manufactured and applied as steel plant castings in our steel works. Resistance to growth and scaling and tensile properties at elevated temperatures of the following 3 groups castings were studied.
  1 st groups; low Cr, low Ni-Cr, high Si-Al and ordinary ductile cast iron.
  2 nd groups; high Si ductile and low Cu cast iron, low Cr and low Al-Cr cast iron.
  3 rd groups; alumerized (hot dip aluminized) or calorized low Cr and low Al-Cr cast iron.
  As the result, maximum allowable temperature was found to be a little higher than 1000°C for high Si ductile cast iron, 1000°C for high Al-Si and annealed alumerized or calorized low Cr cast iron, 950°C for high Si cast iron, 900°C for Al cast steel and ordinary ductile cast iron and 700°C for low Cr and low Ni-Cr cast iron.

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  It has been reported that, by effect of calcium, stability of cementite in steel or cast iron reduced and a remarkable graphitization took place. This effect of calcium was again studied from the aspect of malleable cast iron, in this report.
  The results obtained were as follows:
  (1) By the treatment with calcium silicide, the first stage graphitization and the second stage ones were remarkably promoted and, with same amount of silicon, these rates were several times as big as the ones of plain cast iron.
  (2) Cast Iron treated with calcium silicide could graphitize even in silicon content under 0.5%.
  (3) It was, however, hard for molten iron treated with calcium silicide to solidify in state of white cast iron in sand mold.

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  During the last several years, of many fundamental and practical experiments about the combustion and slag control of basic melting, the original process for the basic melting has been successfully developed, using 650mmφ dolomite lined basic cupola, which enables us to secure the lower cost of metallic charge as well as cutting coke ratio than the same condition of acid melting.
  Superior features of this basic iron have been revealed in several respects, such as lower contents of inclusions, sulphur and phosphorus, and better adaptability in making the nodular graphite iron as well as for the general structural use.

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  Experimental and practical investigations have been made on the characteristics of the distributions of dust particles. Rōken Dust Counter was used in measuring in horizontal and vertical planes. Number of dusts per cubic cm. air and sizes of each particle were measured.
  Dusts were generated by compressed air in artificial dust generation experiment, and in practical investigation sampling was made at the places “shake out, knock out, old sand treatment, etc”.
  Thus, the following results were obtained.
  1. The majority of dust particles in air are of below one micron in diameter. Numbers of dust particles are smaller above the generating point and few in the space of less than one meter in height.
  2. Distributions of dust particles have the same tendencies regardless of their size, if the number of dust particles per cubie cm air is represented in ratio taking the number of dust particles at any one point as the standard.
  3. The fine particles below one micron flow obliquely upward and scatter in wide space. Fine particles of dust below one micron are floating widely in the space of overhead travelling crane, too.
  4. Number of dusts on each foundry work differs widely, but their distribution has the same tendencies. As the distance from the generating points increases, the number of dusts is reduced rapidly. About ninety percent of dust particles are below one micron.

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