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1.7225 | 42CrMo4 +HL nitrocarburised

Numeric designation1.7225
Chemical designation42CrMo4
State+HL nitrocarburised
Etching3% Nital

This sample was nitrocarburised and lies in the lower range of the alloy bandwidth with regard to the chemical composition of the base material. For better contrast of the dark oxide layer, the sample was tightly wrapped with Al foil and hot embedded. You can find more information about this method here.
The compound layer consists of a thin oxide layer and a pore fringe. The diffusion zone is etched slightly darker. The basic structure consists of upper bainite with pronounced segregations.

  • Oxide layer OLT: 4.2 µm
  • Pore fringe (including oxide layer): 17.9 µm
  • Compound layer thickness VS | CLT: 32.0 µm