Degraded graphite
Disintegrated graphite is deformed, finely divided graphite precipitate in cast iron. It results from overloading or chemical reactions and leads to weaknesses and cracks.
Physical-Chemical Mechanism of Action
Graphite in cast iron consists of fine lamellar layers of carbon. Under high temperatures or chemical influences, this graphite can crumble and become a finely dispersed state.
Metallurgical Relevance & Welding Risks
Disintegrated graphite leads to significant cross-section weakening in the weld. This increases susceptibility to cracking and reduces the toughness of the material. Improper handling can cause hot cracking or uneven distortion.
Workshop Practice & Action Guidelines
To avoid the occurrence of disintegrated graphite, it is important to carefully control the melting temperature and cooling time. Too fast cooling can cause the graphite to crumble. If suspected, additional tests should be performed to ensure the graphite remains in its compact form.