1.1274 | C100S +QO +T Hardened and tempered (quenchant: oil)
| Numeric designation | 1.1274 |
|---|---|
| Chemical designation | C100S |
| State | +QO +T Hardened and tempered (quenchant: oil) |
| Etching | 3% Nital |
This hypereutectoid steel (sheet material with cross section = 2 x 30 mm) with 0.98 % carbon (measured with OES; nominal: 0.95 – 1.05 %) was austenitized at 810 °C for 30 min, quenched in oil and then tempered at 250 °C for 2 hours.
The microstructure consists of martensite and secondary cementite (partly in the form of double carbides) both at the rim and in the core. The hardness in both areas is around 710 HV5. Due to the thin plate thickness, complete through-hardening of the specimen was possible despite the absence of alloying elements. Here [Link] there is the same material for comparison, hardened and tempered with the same parameters, but quenched in water instead of oil.
Based on the microstructure, the two quenchants cannot be distinguished, but the sample quenched in oil shows a slightly higher hardness (710 HV5 compared to 693 HV5). A C100S should also be hardened in oil, since water has a too harsh quenching effect.
