抄録
As to alloy white cast irons containing Ni or Cr or both elements cast in various moulds, the cast structures, and dilatometric change in heating and cooling have been observed. C.C.T. curves and T.T.T. curves of these alloys have been measured by dilatometric and microscopic methods. The concentration of Ni or Cr in austenite grains has been calculated by chemical analysis of the alloying element in cementite of cast irons, isolated by electrolitic method. The result obtained can be summarized as follows: (1) Proeutectoid cementite, whose precipitation is observed by the contraction of specimen at high temperature, is not completely precipitated, when the Ni or Cr content of the alloy is sufficiently high, or the specimen is cast in iron or sand mould. (2) The concentration of Ni or Cr in austenite grains depends upon the freezing rate.
