Tempering temperature
The target temperature during the tempering process, which is precisely tuned to the desired hardness and toughness value of the steel. Higher tempering temperatures drastically reduce hardness in favor of increased impact toughness.
Tempering after hardening is a balancing act: If you make it too hot, the structure becomes too soft and the weld loses its strength. If you leave it too low, the steel remains hard and brittle, then the part breaks under load. You always have to adjust the temperature to the respective steel and the intended use. If you hit the right temperature, you get a tough yet wear-resistant structure that doesn't crack as quickly. And important: Keep the temperature constant during tempering so that the workpiece heats through evenly.