Interstitial foreign atom distortion
Interstitial foreign atom distortion: Small atoms like carbon, nitrogen, or hydrogen in interstitial lattice sites distort the lattice and increase strength. However, too high concentrations can also lead to destruction of the crystal structure.
Physico-Chemical Mechanism of Action
Small atoms like carbon, nitrogen, or hydrogen (foreign atoms) pass through interstitial sites in the metal lattice. They distort the lattice and affect the crystal structure.
Metallurgical Relevance & Risks in Welding
The Interstitial Foreign Atom Distortion increases the strength and toughness of the material by distorting the lattice. However, too high a concentration of these atoms can lead to destruction of the crystal structure, which can result in softness or even deformability of the metal. This can occur especially at high temperatures and during long heat treatments.
Workshop Practice & Action Guidelines
To control the Interstitial Foreign Atom Distortion, it is important to carefully select welding materials and processes. At high temperatures and during long heat treatments, the concentration of carbon and nitrogen in the metal lattice should be minimized. This can be achieved by choosing the appropriate shielding gas and the correct welding parameters.