Back (Edge zone)

1.7225 | 42CrMo4 +HL gas-nitrided

Numeric designation1.7225
Chemical designation42CrMo4 +HL
Etching3% Nital

This sample was gas nitrided and lies in the lower range of the alloying range with regard to the chemical composition of the base material.
To obtain a better contrast between the compound layer and the embedding medium, the sample was tightly wrapped with aluminium foil and hot embedded. You can find more information about this method here.
The compound layer shows a typical pore fringe. The diffusion zone is etched slightly darker. The basic structure consists of upper bainite with pronounced segregations.

Pore fringe: 10 µm
Compound layer thickness VS | CLT: 16.7 µm