Peritectic Transformation
Peritectic transformation: On cooling, a liquid phase together with a solid phase forms a new solid phase. This leads to coarsening of the microstructure and can reduce toughness.
Physikalisch-chemischer Wirkmechanismus
In peritectic transformation, a new solid phase forms during cooling together with an existing solid phase. This process leads to coarsening of the metal structure, as crystal sizes grow.
Metallurgical Relevance & Welding Risks
Peritectic transformation can reduce the toughness and elastic modulus of a steel. It can also lead to increased susceptibility to cracking, especially when the metal is under mechanical load. This is particularly critical in highly stressed components or in weld joints under high pressure.
Werkstattpraxis & Handlungsanweisungen
To avoid peritectic transformation, the metal should be cooled as quickly as possible. This can be achieved by a high cooling rate or by using cooling water. When selecting the welding process, make sure it does not cause transformation into peritectic. For highly stressed components, it is advisable to use metals with a low tendency to peritectic transformation.