Face-centered cubic crystal lattice
The face-centered cubic crystal lattice is the basic lattice of austenite with twelve neighbors per atom. It allows high solubility for interstitial atoms and gives steel its characteristic properties.
Physicochemical Mechanism of Action
The face-centered cubic (FCC) crystal lattice has a specific arrangement of atoms in a cubic lattice with atom sites at the corners and in the center of each face. This lattice allows a high density of interstitial solutes, such as carbon or silicon, without disturbing the crystal lattice.
Metallurgical Relevance & Welding Risks
The face-centered cubic lattice is typical for austenite and gives steel its high toughness and formability. However, if cooled too quickly, it can transform to a martensitic structure, which increases hardness but at the same time reduces ductility and formability. This can lead to hot cracks and damage.
Workshop Practice & Action Instructions
To maintain the face-centered cubic lattice during welding, it is important to perform a controlled cooling. This can be achieved by using cooling water or special cooling jackets to limit the cooling rate. The optimal cooling time should be between 5 and 25 seconds, depending on the steel type and weld thickness.