Back (Fe-Base)

1.0535 | C55 +QW +T quenched (in water) and tempered

Numeric designation1.0535
Chemical designationC55
State+QW +T Quenched and tempered
Etching3% Nital

This hypoeutectoid steel (bar material with ⌀ = 27 mm) with 0.5 % carbon (measured with OES; nominal: 0.52 – 0.6 %) was austenitised at 850 °C for 30 min, quenched in water and then tempered at 250 °C for 2 hours. The microstructure consists entirely of tempered (cubic) martensite at the edge; towards the centre of the sample, more and more fine-striped perlite (troostite) forms. In the core, besides tempered martensite and  troostite, there is also some bainite.

The average core hardness is 508 HV5.