Hello everyone, I am the youngest girl in the factory.
Porosity is one of the most common defects in castings.
Today we will learn about: classification,
formation and control of stomata.
Stomata are generally classified into precipitation stomata,
intrusive stomata and reactive stomata.
One, in the process of cooling and solidification of liquid metal,
due to the decrease of gas solubility,
the pore formed by the precipitation gas too late to escape
is called precipitation pore.
Such pores are mainly hydrogen pores and nitrogen pores,
which are scattered and distributed in the section of the casting,
especially in the final solidification part,
such as: near the riser, the center of the hot joint is the most dense;
Two, the gas generated by the high temperature of the liquid metal,
such as the casting mold and the core,
invades the pores formed inside the metal,
and the pores formed by the molten metal involved in
the gas during the filling process are called intrusion pores.
Three, intrusive pores are characterized by a small number,
large volume, smooth pore walls, and an oxidized surface,
which often appear on the surface or near-surface layers of castings.
The shape is mostly pear-shaped, oval or round,
Follow me to learn more about casting knowledge~
See you next time~
Porosity is one of the most common defects in castings.
Today we will learn about: classification,
formation and control of stomata.
Stomata are generally classified into precipitation stomata,
intrusive stomata and reactive stomata.
One, in the process of cooling and solidification of liquid metal,
due to the decrease of gas solubility,
the pore formed by the precipitation gas too late to escape
is called precipitation pore.
Such pores are mainly hydrogen pores and nitrogen pores,
which are scattered and distributed in the section of the casting,
especially in the final solidification part,
such as: near the riser, the center of the hot joint is the most dense;
Two, the gas generated by the high temperature of the liquid metal,
such as the casting mold and the core,
invades the pores formed inside the metal,
and the pores formed by the molten metal involved in
the gas during the filling process are called intrusion pores.
Three, intrusive pores are characterized by a small number,
large volume, smooth pore walls, and an oxidized surface,
which often appear on the surface or near-surface layers of castings.
The shape is mostly pear-shaped, oval or round,
Follow me to learn more about casting knowledge~
See you next time~
