Back (Fe-Base)

1.1231 | C67S+I

Numeric designation1.1231
Chemical designationC67S
StateI (isothermally hardened)
Etching3 % Nital

The microstructure images show a spring steel that has been isothermally quenched and tempered. The hardness is 540 HV1. There is lower bainite, which is quite coarsely needled.