Kaldbearbeiding

Kaldbearbeiding, a Norwegian term, translates to "cold processing" or "cold working" in English. It refers to a group of metal forming processes that are carried out at or near room temperature. Unlike hot working, which involves heating the metal to a malleable state, cold working significantly increases the strength and hardness of the metal through a phenomenon known as strain hardening or work hardening.

The primary methods of kaldbearbeiding include cold rolling, cold drawing, cold forging, and extrusion. Cold rolling involves passing metal through rollers at room temperature to reduce its thickness and improve its surface finish and dimensional accuracy. Cold drawing is used to reduce the cross-sectional area of a metal rod or wire by pulling it through a die. Cold forging shapes metal by applying compressive forces at room temperature, often resulting in complex shapes with high strength. Cold extrusion involves forcing metal through a die under high pressure, typically to create rods or tubes.

Kaldbearbeiding offers several advantages, such as improved mechanical properties like tensile strength and hardness, excellent surface finish, and precise dimensional control. However, it also requires higher forces and can introduce residual stresses into the material. Metals that have undergone cold working may become more brittle and require annealing to restore ductility if further forming or machining is needed. This technique is widely used in various industries, including automotive, aerospace, and manufacturing, for producing components that require high strength and accuracy.