日本金属学会誌

J. Japan Inst. Metals, Vol. 28, No. 12 (1964),
pp. 815-820

Solidification of Wedge-shaped and T-shaped Steel Castings

Ren Obata1

1Technical Research Laboratory, Nippon Sharyo Seizo Kaisha, Ltd., Nagoya

Abstract:

Studies were made on solidification of wedge-shaped and T-shaped steel castings in sand mould by observing their cooling curves together with pour-out tests.
Experiments were carried out on: (1) three wedge shapes with tapers varying from 1/5 to 1/15. (2) a plate, 200 mm in height, 300 mm in length and 25 mm thick joined to a 100 × 100 × 200 mm square bar to form a stub-head T. (3) T-shapes of three different sizes with uniform head-bar dimensions, but their legs are varied both in length and thickness.
The results obtained were as follows.
All measurements were taken at the midheight plane of castings.
(1) For each wedge shape, solidification times at points on the centreline of the wedges were proportional to a square of the thickness except in the vicinity of the thickest end.
(2) In stub-head T, it was found that the zone length in the leg plate from the fillet corner wherein the solidification was retarded by the thermal effect of the heavy head, was equal to the thickness of the leg plate.
(3) Solidification times of various T-shapes were considered to be in two portions, i. e., the joined portion and the plate portion.
The solidification time of each portion was proportional to a square of the volume to the surface area ratio (V/A), i. e., t=(1/q2)(V/A)2.
Solidification constant q was found to be 0.86 mm/sec1/2 for the mould bonded by sodium silicate.
A formula for calculation of (V/A) of T joind portion are given as follows:

(V/A)j = \frac{(2T12+T22+T1T2)W}{(4T1+3T2)W+2(2T12+T22+T1T2)},
\hskip4pt Where\hfill T1:thickness of the T-shaped head
\hfill T2:thickness of the T-shaped leg
\hfill W:width (or hight in this case) of the plate.


(Received 1964/7/1)

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