Question

When casting low carbon steel under certain mold conditions, the mold constant in Chvorinov's rule = 4.0 min/cm2. Determine how long solidification will take for a rectangular casting whose length = 30 cm, width = 15 cm, and thickness = 20 mm.

Answer 1

Answer:

Solidification time is 2.78 min.

Explanation:

Chvorinov's rule states that the solidification time is directly proportional to the square of ratio of total volume to the total surface area of the cast.

Step1

Given:

Chvorinov's rule constant is 4 min/cm².

Length of the rectangular cast is 30 cm.

Width of the rectangular cast is 15 cm.

Thickness of the rectangular cast is 20 mm or 2 cm.

Calculation:

Step2

Volume of the cast is calculated as follows:

$V=l\times b\times t$

$V=30\times15\times2$

V = 900 cm³.

Step3

Total surface area is calculated as follows:

A=2(lb+bt+tl)

$A=2(30\times15+15\times2+2\times30)$

A=1080 cm².

Step4

Time of solidification is calculated as follows:

$t=K(\frac{V}{A})^{2}$

$t=4(\frac{900}{1080})^{2}$

t = 2.78 min.

Thus, solidification time is 2.78 min.