HARDENING & tempering
The heat treatment method of steel consisting of the rapid cooling in water or oil from a temperature above the conversion temperature with subsequent application to a relatively high temperature (above 500 ° C), increasing the toughness of the material while reducing the hardness.
The method gives a big difference to the flow rate/stiffness, and good ductility.
If you only austenitize and cool the detail, you call the process martensitization. If you also carry out the subsequent warming, called annealing, you call it all sealing. By varying the operating temperature and the time of application, you can control the hardness and toughness of the material within fairly wide limits.
The end result is properly corrosion-resistant material with a significantly higher hardness than the starting material and slightly deteriorated toughness. Provides better strength properties than in normalized state.