Ledeburite I Network
Ledeburite I network is a hard microstructure in white cast iron, consisting of austenite and cementite. It forms with hypoeutectic additions and protects the weld.
Physical-Chemical Mechanism of Action
The ledeburite-I network forms from the slow cooling of white cast iron with hypoeutectic additions. It forms a stabilized austenite lattice surrounded by cementite. This prevents the formation of glass-hard copper alloys and improves mechanical strength.
Metallurgical Relevance & Welding Risks
A fine ledeburite-I network protects the weld from corrosion and increases its toughness. However, cooling too fast can result in excessive hardness, leading to cracks and hot cracks. Cooling too slowly coarsens the grain and reduces strength.
Workshop Practice & Instructions
To create an optimal ledeburite-I network, cool the white cast iron slowly (t8/5 > 20 s) and avoid excessive cooling rates. A cooling time of 30 to 40 seconds is ideal. Monitor the cooling curve closely and adjust the cooling temperature to stabilize the structure.