The S-curves of 0.5%Mo-1.3%Cu cast irons containing 0.26 or 0.87% of aluminum and 0.12 or 0.26% of titanium were determined by metallographic and dilatometric methods. For subsequent experiment, cast irons containing 0.2 to 1.2% molybdenum and 0.5 to 2.3% copper were remelted in an alumina crucible, using a Tamman furnace. After addition of aluminum and titanium, molten iron was poured into sand mould to investigate the structure and hardness.
  The isothermal pearlite transformation was retarded by the addition of aluminum, but in bainite range was not affective. By the addition of titanium, the transformation were extremely accelerated and S-curve moved to the left in both ranges of pearlite and bainite, and also the nucleation of both reactions was independed by inclusions of titanium compounds.
  From the result of casting experiments, it was concluded as follows : Addition of aluminum showed a tendency to promote the formation of acicular bainite and to decrease pearlite matrix in the Mo-Cu cast iron studied. By addition of titanium, an acicular matrix having low hardness appeared in higher alloyed irons, which consisted of almost martensite matrix without its addition.

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  Not a small amount is spent on the brake shoes in the expenditures of railway maintenance. And great efforts have been made to cut down this expense.
  As a result of adapting High Phosphorus Cast Iron Brake Shoes, Kinki Nippon Railway Company has succeeded in cutting down much of the cost, by prolonging its life more than 45% in the year 1959 as compared with that of 1951. This reprot shows the following two points which prove the superiority of High Phosphorus Brake Shoes.
  These results were obtained both by actual car tests and by laboratorial test. 1. It is possible to say that High Phosporus Cast Iron Brake Shoes of Kinki Nippon Railway Co. specification of about H.B.250 wear almost 20% less than most widely used Low Phosphorus Brake Shoes of about H.B.220. 2. When the effect on the wear of tire wheels is considered, it is also possible to say that when Low Phosphorus Cast Iron Brake Shoes are used, the degree of wear runs parallel with the hardness of the material. But when High Phosphorus Cast Iron Brake Shoes are used no tendency as mentioned above can be found, and it is also made clear that the use of High Phosphorus Cast Iron Brake Shoes is good for both wheels and Brake Shoes.

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  A study was carried out to find the influence of the melting condition−temperature and holding time of melt after the addition of ferro-silicon−on the graphitization and the casting structure of white cast iron containing about 3% carbon and 1% silicon. The behavior trends of the melting condition were discussed in connection with the amount of gaseous elements existing in iron. From the results, the changes in the rate of graphitization and the casting structure of white iron primarily seems to be due to a change in the amount of the gaseous elements which has respect to the melting condition.
  It is concluded that the graphitization becomes difficult with increasing the amount of iron oxide and nitrogen, but the influence of nitrogen content is not appreciable at the first stage graphitization, and that the finer structure of white iron is obtained with increasing the amount of silica, or with decreasing the amounts of iron oxide and nitrogen.

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  The thin and extended projection on the castings, i.e. “selfcooling fin”, absorbs heat from the cast body so rapidly that the freezing time is sufficiently reduced. The thinner and more widely extended fin is found to be more effective to a degree, but the critical size of the fin may be neccessarily decided not only on the technical and economical bases but also on the problem of heat flow.
  Chilling effect of the fin was observed on the case of the bar castings of pure aluminium. The results obtained were as follows. The fin 2.5-4.0mm. in thickness and 15-20 times in width is found to be most successful, while the optimum size of the bar castings is t/D=0.08-0.16. The freezing time of the castings is shortened by 45-50% in this condition. The cooling curves obtained in the center of the castings and at the joints and ends of the fins during solidification are suitable evidences for the phenomenon above noted. These fins have a generous cooling effect and are able to substitute for the conventional chill.
  The application of the fins to promote directional solidification is also described. The fins properly arranged expand the sound areas and prevent formation of the hot spots in the heavy sections. The fins on the tin bronze castings are not so effective but ones on the high-strength yellow brass casting are so effective as they substitute for the cast iron chill 7-9mm. in thickness. A consideration is also turned toward the combined use of the several fins on the high-strength yellow brass and aluminium bronze castings. It is found that the most successful distance between each fin is approximately 20mm.

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  Mechanical properties of test piece made from the cylinder of the rock drill with complicated form design which was cast centrifugally, are investigated and following results are obtained.
  1) As cast, changes of tensile strength, elongation and reduction of cross sectional area have no relation with revolving rate.
  2) As annealed, mechanical properties are proportional with revolving rate, minimum accerelation to improve the mechanical properties seems to be 90. G.
  And also, how lead in lead-free cutting steel which has been utilized recently, segregates by centrifugal casting and its influences on impact value of centrifugal lead-steel castings are described.

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