Ledeburite I

The primary eutectic microstructure consisting of austenite and cementite, formed during the solidification of iron-carbon alloys with a carbon content exceeding 2.06 mass percent. Upon further cooling, the austenite contained within transforms into secondary cementite and pearlite.

Ledeburite is a very hard and brittle structure that occurs in high-carbon steels. When welding such materials, you have to be careful not to get hot cracks. The structure is unstable and sensitive to cooling. Cooling too fast makes the material glass-hard and barely workable, cooling too slowly coarsens the grain and makes it tough. So you have to control the cooling to prevent the steel from cracking or losing its toughness.

MetallurgieSchweißtechnik