Today, a foundry in the Hangzhou area encountered
the problem of loose castings.
The casting in question is a motor base product,
the material is required to be 250 grades,
the weight is 47 cents, the height is 47 cm,
and the wall thickness is 30 mm at the thick wall
and 7 mm at the thin wall.
According to the manufacturer's response,
the casting has always been loose in the thick wall recently,
and there is leakage under pressure.
In the production of gray cast iron,
white defects of thin-walled parts and loose defects
of thick-walled parts are the most troublesome things for foundries.
Let's not talk about other elements,
just from the carbon silicon manganese index.
The manganese index is obviously low,
which will cause the content of pearlite to be low,
the ferrite to rise, and the effect of manganese to
inhibit the precipitation of graphite is weakened.
As a result, flake-like coarse graphite appears in the piece,
and looseness is formed at the thick wall of the casting.
Follow me, the youngest girl in the factory,
we will continue to talk about the reasons for
this looseness in the next issue
the problem of loose castings.
The casting in question is a motor base product,
the material is required to be 250 grades,
the weight is 47 cents, the height is 47 cm,
and the wall thickness is 30 mm at the thick wall
and 7 mm at the thin wall.
According to the manufacturer's response,
the casting has always been loose in the thick wall recently,
and there is leakage under pressure.
In the production of gray cast iron,
white defects of thin-walled parts and loose defects
of thick-walled parts are the most troublesome things for foundries.
Let's not talk about other elements,
just from the carbon silicon manganese index.
The manganese index is obviously low,
which will cause the content of pearlite to be low,
the ferrite to rise, and the effect of manganese to
inhibit the precipitation of graphite is weakened.
As a result, flake-like coarse graphite appears in the piece,
and looseness is formed at the thick wall of the casting.
Follow me, the youngest girl in the factory,
we will continue to talk about the reasons for
this looseness in the next issue
