Question 7.13: Design of Links for a Chain Design a ductile cast iron chain......
Design of Links for a Chain
Design a ductile cast iron chain (Figure 7-27) to operate in a furnace used to fire ceramic bricks. The chain will be used for five years at 600°C with an applied load of 5000 lbs.
From Figure 7-26(b), the Larson-Miller parameter for ductile cast iron is
L. M. = \frac{T(36 \ + \ 0.78 \ \ln \ t)}{1000}
The chain is to survive five years, or
t = (24 h/day)(365 days/yr)(5 yr) = 43,800 h
From Figure 7-26(b), the applied stress must be no more than 1800 psi.
Let us assume a factor of safety of 2, this will mean the applied stress should not be more than 1800/2 = 900 psi.
The total cross-sectional area of the chain required to support the 5000 lb load is
A = F/S = \frac{5000 \ lb}{900 \ psi}=5.56 \ in.^2
The cross-sectional area of each “half” of the iron link is then 2.78 in.² and, assuming a round cross section
d² = (4/π)A = (4/π)(2.78 in.²) = 3.54 in.²
d = 1.88 in.
