Work Hardening / Strain Hardening
Cold working increases the strength and hardness of metals through plastic deformation below the recrystallization temperature. The microstructure remains unchanged.
Physicochemical Mechanism
Below its recrystallization temperature, the metal deforms plastically without forming new crystal grains. This leads to an increased number of strain fields in the structure.
Metallurgical Relevance & Welding Risks
Cold working can increase the hardness and strength of the weld, which improves its mechanical properties. However, it can also lead to hot cracking if the metal is deformed too much. This is especially a risk with high-strength steels.
Workshop Practice & Instructions
Use cold working to improve the mechanical properties of weld areas. Make sure the metal is not deformed excessively to avoid hot cracking. Deformations between 1% and 5% are recommended. With high-strength steels, careful control of deformation is essential.