1.0503 | C45 Incorrect induction hardened

During induction hardening, fine-striped perlite (troostite) has formed in the surface layer due to an insufficient cooling rate.
In addition to martensite and fine-striped perlite, bainite, which is partly arranged in a network, is also present at the edge. Towards the core, the quenching rate decreases more and more, so that the bainite content increases steadily here (location 2). In the transition area, ferrite formation also begins in a network-like arrangement. In the core, the microstructure consists exclusively of ferrite and pearlite. The ferrite is arranged along the pearlite grain boundaries and partly shows a Widmannstätten structure (needles).

An etching with our PAG QT² impressively shows the grain structure.
Particularly interesting here is also the comparison to the case study 1.0503 | C45 Induction Hardened, where there was no hardening defect.