1.0501 | C35 +QW +T quenched (in water) and tempered
| Numeric designation | 1.0501 |
|---|---|
| Chemical designation | C35 |
| State | +QW +T quenched (in water) and tempered |
| Etching | 3% Nital |
This hypoeutectoid steel (bars with 14 mm diameter) with 0.34% carbon (ICP-OES) was austenized at 850°C for 30 min, quenched in water and tempered for 2 hours at 250°C. The austenitizing temperature is in the correct range for this material (840 – 880 °C). Due to the carbon content, annealing in the middle range of the temperature range makes sense. Near the surface, the microstructure is fully martensitic. In the core, fine-striped pearlite (troostite) is found in the martensitic matrix.
C35 is a shell hardener. Due to the small diameter of the specimen and the lack of alloying elements, the upper critical cooling rate was not reached in the core. Therefore, in addition to martensite, rosettes of fine-striped pearlite have formed at grain boundary spandrels.
