Tertiary carbide

Finest carbide precipitates that segregate directly from the supersaturated ferrite lattice at low temperatures. These phases contribute to microstructural stability and secondary hardening in specific alloyed steels.

You don't want to promote tertiary carbides when welding. They form during heat treatment or incorrect cooling and make the structure hard and brittle. When welding carbon-rich steels, you must watch the cooling rate, otherwise you'll get hard spots that you can't machine later. Keep the interpass temperature low and let the part cool slowly, then you won't have problems with the structure.

MetallurgieSchweißtechnik