There are seven kinds of typical poor metallurgical phenomena in ductile iron,
they are worm-like graphite, lump-like graphite,
grass like graphite, graphite ball is not rounded,
graphite floating, surface reaction layer, linear arrangement of graphite.
In today's episode, I'll focus on the first two phenomena.
one, worm-like graphite: mainly because the spheroidization process is not good,
residual Mg, residual RE amount is insufficient.
The holding temperature is too high or the holding time is too long.
The original molten iron has a high content of S
and does not have enough Mg to balance it.
two, crushed graphite: mainly because of high RE content,
raw material is too pure, CE is too high, pouring temperature is too high.
Therefore, Sb is required to neutralize RE,
properly adjust CE value and pouring temperature.
Pay attention to me, the youngest girl in the factory,
next time you will continue to understand
the metallographic adverse reactions of ductile iron ~
they are worm-like graphite, lump-like graphite,
grass like graphite, graphite ball is not rounded,
graphite floating, surface reaction layer, linear arrangement of graphite.
In today's episode, I'll focus on the first two phenomena.
one, worm-like graphite: mainly because the spheroidization process is not good,
residual Mg, residual RE amount is insufficient.
The holding temperature is too high or the holding time is too long.
The original molten iron has a high content of S
and does not have enough Mg to balance it.
two, crushed graphite: mainly because of high RE content,
raw material is too pure, CE is too high, pouring temperature is too high.
Therefore, Sb is required to neutralize RE,
properly adjust CE value and pouring temperature.
Pay attention to me, the youngest girl in the factory,
next time you will continue to understand
the metallographic adverse reactions of ductile iron ~
