In hot forming, a sector of forming technology, workpieces are heated so that they can be formed with less effort. In the forming technology, a distinction is made between cold, warm and hot forming. When metals are heated, the component resistance is reduced, thus facilitating forming. Depending on the alloy, the temperature is approx. 40-60% of the melting temperature of the components and is above the recrystallization temperature. The advantages of hot forming are in particular the low forming forces and the high formability. Higher scale formation and possible component distortions have a disadvantageous effect.
Hot forming is used in particular for highly stressed components such as shafts or cylinders. The process is also used in sheet metal forming. In the course of press hardening, manganese-boron steels are hot-formed as sheet metal above the austenitizing temperature (usually over 900 °C). This enables a targeted structural transformation to increase strength through martensitic hardening. In addition to the increase in strength, the use of material resources is also lower. At the same time, possible scaling layers are prevented with special coatings such as AlSi layers. The hot forming of sheet metal is used in particular for safety-relevant bodywork elements.