Interstitial solid solution
Interstitial solid solutions are formed by inserting small foreign atoms into crystal lattice voids. This increases strength but can also lead to hardening and porosity.
Physical-Chemical Mechanism of Action
Interstitial solid solutions are formed by inserting very small foreign atoms (such as carbon or silicon) into the empty lattice sites of a metal. These atoms squeeze into the lattice gaps and cause mechanical stresses in the material.
Metallurgical Relevance & Welding Risks
These stresses can increase the strength of the material because they stabilize the crystal lattice. However, too high concentrations of interstitial atoms also lead to hardening and an increased susceptibility to pore formation. This can cause weld defects such as hot cracking or fine cracks.
Workshop Practice & Instructions
To effectively control interstitial solid solutions, it is important to regulate the melting process and cooling steps precisely. Avoid excessively high melting temperatures and ensure controlled cooling to minimize stresses. For highly hardened steels, it may be helpful to perform austenitizing before welding to balance the interstitial atoms.