Process Solution for Cold Shut Defect in Lesser Wall Thickness Castings

Abstract

Foundry defect is uncertainty which unable to
meet customer defined specifications. Customer
not accept parts with defective appearance
because of stress concentration is found at
irregularities observed area which may leads to
failure during try to promote his function when
its assembly done at customer end. Some defects
are tolerated but defect with higher irregularities
directly get scrapped. So, foundry industries
should control defects while production process
going on, for that need proper guideline & well
process control. The defect like Cold shut come
suddenly in foundries with higher rejection rates
due to that parts get rejected. Behind cold shut
defects number of causes such as molten metal
temperature, green sand temperature, chemical
composition, pouring metal fluidity. So, need to
find correct cause behind cold shut defect with
taking reference of observed location & casting
geometry. As we know history of cold shut defect,
it mostly found in castings which have less wall
thickness mostly having wall in between 4-8 mm.
Foundry industries most of times facing cold shut
problem in final casted product & unable to
control due to fail to diagnosis of correct cause
behind this defect. My research is conducted
Mane foundry who having one part is name
Drum sprocket which belongs to two-wheeler
manufacturing industries with good casting
weight is 2.65 Kg & smaller wall thickness varies
in between 3.8-4.0 mm so at lesser wall thickness
area found cold shut defect. My paper shows how
it get minimized totally with minor modifications
in current manufacturing process. I hope it will
most beneficial for world foundry industries to
get good results.