荒されの研究

—鋳造における湯の流れについて（第5報）—

抄録

    Cuts and washes which occurred in the vicinity of ingate of a mold and which caused by a high temperature and high speed running of molten metal were studied in this report. In Section 1, the influence of the number of ingates and its shape on cuts and washes was studied and the rate and time of pouring were also studied coating washes on mold surface.
    The relations between the strength of mold and the defects or the relations between the parting easiness and the defects were mentioned in Section 2. The experiment mentioned in Section 2 were carried out without coating any washes on the mold.
    Summarized results taken in Section 1 are as follows.
  1) Cuts and washes occur in front of ingates where the melt runs.
  2) The total volume of cuts and washes is almost equal in every case if the total section area of ingates is equal. When a number of ingates of small size is used and its total section area is constant, the depth of cuts and washes is shallow and the area becomes wider.
  3) The shape of ingate does give little influence.
  4) The relation among three factors such as metal weight to be poured in a unit time M, pouring time T and the total volume of cuts and washes V can be expressed as
            V ∞ M^1.2T⁰.
  5) The degree of the occurrence of cuts and washes becomes greater when the pouring temperature is higher or lower.
  6) Factors like moisture and grain size which govern the adhesivility of wash materials, have great influence on the formation of defects and the prefarable moisture content must be choosen and the smaller grain size gives a good result.
  7) Combustibility of washing material gives great effects.
    The results taken from Section 2 are as following.
  8) The degree of cuts and washes has a proportional relation to the easiness of peel-off the facing sand.
  9) Cuts and washes occur in succession of drying the sands in green state after the pouring is made. But in dry molds, they occur immediately after the pouring.