← Glossary
Cooling rate
The temporal temperature drop per unit time during thermal treatment, which decisively determines the resulting microstructure and hardness. It governs diffusion processes during phase transition.
The cooling rate determines what happens in the microstructure after welding. If you cool too fast, you get a hard, crack-prone structure – in steel, that's called martensite. If you cool too slowly, the structure becomes softer and strength suffers. For high-strength or alloyed steels, you have to control the cooling. You do this via heat input and cooling conditions. If you cool with a water bath, don't use ice-cold water – the material should cool down in a controlled manner, not be quenched suddenly.
MetallurgieSchweißtechnik