1.7225 | 42CrMo4 +QW +T quenched (in water) and tempered
| Numeric designation | 1.7225 |
|---|---|
| Chemical designation | 42CrMo4 |
| State | +QW +T Quenched and tempered (quenchant: water) |
| Etching | 3% Nital |
This hypoeutectoid quenched and tempered steel (bar material with ⌀ = 28 mm) with 0.38 % carbon (measured with OES; nominal: 0.38 – 0.45 %) was austenitised at 850 °C for 30 min, quenched in water and then tempered at 250 °C for 2 hours. The austenitisation temperature is in the correct range for this material (820 – 880 °C), due to the low carbon content an annealing in the upper range of the temperature range is reasonable. The microstructure consists entirely of tempered (cubic) martensite in both the rim and the core. The alloying elements chromium (OES: 1.03 %) and molybdenum (0.21 %) ensure that this steel can harden completely (by hindering C diffusion).
