鋳鋼用鋳型のスプレーの研究

―スプレーによつて起る鋳型表面層の変化について―

抄録

  While many studies have been reported on the properties of casting sand by sand test pieces, after-treatments of moulding sand such as washing have not yet been fully considered
The aftertreatments may be usually applied to green sand or to skin drying mouldings in steel castings, but the reports of the effects of washing to mould surfaces have been scarcely reported to the present.
  So, the author investigated the varions changes caused by washing in steel casting mould surfaces.
  The results obtained are as follows;
  (1) Cracks are caused by washing over the constant quantity (cc/cm²) on moulding sand surface when the sand contracts in constant rate of drying. Especially the intensity of cracks should be large in the non-fixed areas of mould surface layers. The foundry men may consider the possibility that scabs in steel castings are caused by these cracks.
  (2) To some constant sand mixing, the intensity of cracks is proportional to washing quantity (cc/cm²).
  (3) With the excess washing, cracks parallel towards mould surfaces are generated first, vertical ones such as on the boundaries in metal structures next.
  (4) Washing of less moleculer weighted solute solution increases the intensity of cracks.
  (5) The more the washing increases, the less the loss of sand in scraching test decreases.
  (6) The more the sand is coarse, the less the intensity of crucks decreases.