Cold Working
Cold forming shapes metals below their recrystallization temperature, increases hardness, and reduces ductility. Risks include grain coarsening and tool cracking.
Physicochemical Mechanism
Cold forming means plastically shaping metals at temperatures below their recrystallization temperature. Atoms in the crystal structure are rearranged without forming new crystals. This leads to an increase in hardness and a decrease in ductility.
Metallurgical Relevance & Welding Risks
The increased hardness can cause difficulties in welding, as tools wear faster. Coarsening of the grain can impair toughness and conductivity. Additionally, there is a risk of tool cracking if the metal structure is deformed too much.
Workshop Practice & Instructions
To minimize the negative effects of cold forming, temperatures during forming should be carefully controlled. For metals with high grain coarsening tendency (like steel), careful cooling and possibly a heat treatment after forming should be done to regulate grain size and improve toughness.