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Phosphorus (P)

Phosphorus (P) in steel causes hidden segregation and increases susceptibility to fracture, especially at low temperatures.

Phosphorus is generally an unwanted companion in steel. During welding, it tends to segregate, meaning it accumulates at the grain boundaries. This makes the material brittle there and can lead to cracks, especially when the weld cools quickly. So keep the phosphorus content low in the base material and filler metal, then you won't have any problems with it.

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