Temper carbon

Agglomerates of elemental carbon formed through the thermal decomposition of metastable cementite during the annealing process of white to malleable cast iron. This floccular structure noticeably increases the toughness of the material.

Temper graphite forms during annealing from cementite and creates flaky carbon nests in the structure. When welding malleable cast iron, this is an important point: The temper graphite makes the material tough and prevents the weld from cracking. If you cool too fast or get too hot, you won't get a clean structure, the grain coarsens and the part becomes brittle. So control the heat input so that cooling remains controlled and you don't destroy the temper graphite.

MetallurgieSchweißtechnik