Nitrogen Buffer

Physical-Chemical Mechanism of Action

Nitrogen acts as a buffer in the melt and remains embedded in the crystal lattice. It reduces the number of degrees of freedom of atoms, leading to a finer microstructure.

Metallurgical Relevance & Welding Risks

A high nitrogen content increases yield strength and improves resistance to pitting corrosion. However, too high a nitrogen content (> 0.1 %) can coarsen the microstructure, reducing toughness and promoting cracking.

Workshop Practice & Action Guidelines

For austenitic steels, use a nitrogen buffer in the melt. Ensure the nitrogen content does not exceed 0.1 %. If the nitrogen content is too high, the microstructure can coarsen and toughness is reduced.