1.1191 | C45E +N Normalised at 850 °C (cooled with compressed air)
| Numeric designation | 1.1191 |
|---|---|
| Chemical designation | C45E |
| State | Normalised at 850 °C (cooled with compressed air) |
| Etching | 3% Nital |
This hypoeutectoid steel (bar material with ⌀ = 20 mm) with 0.43 % carbon (measured with OES) was normalised at 850 °C and then cooled with the help of compressed air. The microstructure consists, typical for this material and heat treatment condition, of ferrite and fine and ultra-fine-grained pearlite. Compared to the furnace-cooled C45E, the microstructure is significantly finer-grained. The edge layer is covered with scale (dark grey) and shows a surface decarburisation of approx. 200 µm (more than in the furnace-cooled sample). The average core hardness is 207 HV5 (compared to 174 HV5 for the furnace-cooled sample).
