Die Entstehung der Karbide in der Phasengrenze zwischen Deltaferrit und Martensit bei 9-14% Chromstählen

Materials with a sufficient toughness have to be used for safety-relevant components. In martensitic 12% chromium steels delta ferrite may occur, at higher contents (> 0,5 %) the fracture toughness of the material may be reduced considerably. This means that the DBTT (ductile to brittle transition temperature) is shifted towards higher temperatures during impact tests. In two-phase steels consisting of delta-ferrite and martensite, this behavior of brittle fracture is found to be caused by the massive dendritic carbide surrounding the delta-ferrite