Thermal Contraction Stress
Thermal contraction stress arises from uneven cooling of components, leading to local stresses and endangering integrity.
Physicochemical Mechanism of Action
Thermal contraction stress occurs when parts of a workpiece cool at different rates. The faster-cooling areas contract while the slower-cooling areas remain expanded. This localized mismatch leads to stress in the material.
Metallurgical Relevance & Welding Risks
These stresses can cause cracks and distortion in the components, especially when they exceed the material's elastic limit. They jeopardize component integrity and can lead to malfunction or failure of the parts.
Workshop Practice & Action Items
To minimize thermal contraction stress, ensure even cooling. This can be achieved by using cooling water or cooling gas. For large components, it helps to incorporate cooling channels or arrange cooling bars. Keep the maximum stress below the material's elastic limit to avoid cracks.