Shrinkage in Large ductile iron casting
Shrinkage in Large ductile iron casting
(OP)
Dear all,
I have a large ductile iron casting ~250lbs with a wall thickness of 1 inch in resin bonded sand.
I got shrinkage issues that I can't seem to get rid off.
Chemistry :
C: 3.82
Si: 2.65
Mn .449
S 0.0108
Cu 0.0765
Mg 0.0319
Cr 0.0262
Pour Temp is 2590F.
Nodularity is great.
Any ideas?
I have a large ductile iron casting ~250lbs with a wall thickness of 1 inch in resin bonded sand.
I got shrinkage issues that I can't seem to get rid off.
Chemistry :
C: 3.82
Si: 2.65
Mn .449
S 0.0108
Cu 0.0765
Mg 0.0319
Cr 0.0262
Pour Temp is 2590F.
Nodularity is great.
Any ideas?





RE: Shrinkage in Large ductile iron casting
_____________________________________
"It's better to die standing than live your whole life on the knees" by Peter Mayle in his book A Good Year
RE: Shrinkage in Large ductile iron casting
I actually tried increasing the C to improve the expansion. That didn't work.
And then I tried to increase pouring T, reduce pouring t to fill it fast before graphitization starts.
I also tried pouring it slow... that didn't work either.
The casting is a pipe and there is shrink along the parting line. Looks more like interdendritic rather than large cavities.
RE: Shrinkage in Large ductile iron casting
You have tried increasing C.E ,which only increases expansion pressure. I hope the molds are rigid, and that there is no mold swell.
_____________________________________
"It's better to die standing than live your whole life on the knees" by Peter Mayle in his book A Good Year
RE: Shrinkage in Large ductile iron casting
It may be hard to keep the mold together though as it is impossible to move the parting line. So I am not sure.. probably I d need to strap it.
I also thought of using a copper pipe inside the core to act as a chiller..?
RE: Shrinkage in Large ductile iron casting
_____________________________________
"It's better to die standing than live your whole life on the knees" by Peter Mayle in his book A Good Year