Kaltgearbeitete

Kaltgearbeitete describes metals and metal products that have undergone plastic deformation at room temperature or near room temperature, primarily to increase strength through work hardening. The term is used in German-language materials science, engineering specifications, and technical literature to distinguish these parts from those that are formed at elevated temperatures.

The cold-working process includes methods such as rolling, drawing, extrusion, bending, punching, and wire drawing performed at ambient temperatures. The deformation increases dislocation density and creates a subgrain structure, which raises yield strength and hardness while reducing ductility and toughness. Residual stresses and anisotropy in properties can also arise from cold working.

Effects of cold working are generally reversible to some extent through annealing or recrystallization. Heating the material above its recrystallization temperature allows new, strain-free grains to form, reducing dislocation density and restoring ductility at the expense of some strength. The degree of reversibility depends on the material and the amount of prior deformation.

Common materials subjected to cold work include steel and stainless steel, aluminum, copper and its alloys, brass, and nickel-based alloys. Applications frequently rely on cold-worked properties for springs, wires, cables, fasteners, tubes, and shaped components where high strength and stiffness are required with relatively low component thickness. The amount of cold work is often quantified as percent reduction in area or true strain, aiding in specification and quality control.

See also: cold working, work hardening, annealing.