Columnar Grain Growth
Columnar grain growth occurs with strong vertical temperature gradients and leads to different mechanical properties in horizontal and vertical directions.
Physicochemical Mechanism of Action
Columnar grain growth occurs when the temperature varies strongly from top to bottom during cooling. This causes the metal to arrange in long, vertical structures (columns).
Metallurgical Relevance & Risks in Welding
This grain growth can lead to increased hardness and toughness in the vertical direction, making mechanical properties uneven. It increases the risk of cracks and fractures, especially under loads acting horizontally.
Workshop Practice & Action Guidelines
To avoid columnar grain growth, the cooling process should be controlled. Use protective shielding or cooling systems that allow uniform temperature distribution. Pay attention to the correct selection of welding material and processes to minimize grain growth.