Eutectic cell
Eutectic cells are spherical growth forms of austenite and graphite in cast iron that form during solidification.
Physical-Chemical Mechanism of Action
During cooling of cast iron, a spherical cell structure of austenite and graphite forms. This process occurs in a specific temperature range, the eutectic, where austenite and graphite crystallize simultaneously.
Metallurgical Relevance & Risks in Welding
Eutectic cells can cause difficulties in welding. The sharp boundaries between cell walls can lead to cracks or distortion, especially if the weld does not penetrate well. Additionally, graphite in the cells can cause hot cracking at high temperatures.
Workshop Practice & Action Instructions
To avoid eutectic cells, cast iron should have the correct composition and controlled cooling should be performed. When welding, it is important to use a high temperature and long heat input to ensure that the cell walls are well penetrated. Avoid rapid cooling methods such as water spray or strong wind.