Weld toe region

The transition zone from the weld bead surface to the unaffected base material. Due to its geometric notch effect, it represents the primary zone for fatigue crack initiation.

The weld transition is the zone right next to the weld seam where the structure has been altered by heat. The material there is treated differently than the rest, and you can quickly get stresses and hardness in there if you're not careful. If you get it too hot or cool it down too fast, the stuff becomes brittle and tears away under load. So watch out that you manage the heat cleanly and don't quench the part, then the transition stays ductile and holds up.

MetallurgieSchweißtechnik