Ledeburitic Residual Microstructure
Ledeburitic residual structure forms when austenitic alloys cool too fast, leading to high wear. It's a mix of austenite and cementite.
Physical-Chemical Mechanism of Action
When austenitic alloys cool rapidly, some austenite remains untransformed, leading to a mixture of austenite and cementite. This residual structure shapes the mechanical properties of the weld.
Metallurgical Relevance & Welding Risks
The ledeburitic residual structure causes high wear and can lead to crack-prone areas. It reduces toughness and the mechanical properties of the weld, which can be problematic especially under high loads.
Workshop Practice & Action Instructions
To avoid the ledeburitic residual structure, it is important to ensure controlled cooling of the weld. This can be achieved by using cooling water or special cooling dies. The cooling rate should be set so that austenite is completely transformed into cementite, without cooling too fast.