Crack tip opening displacement
Crack tip opening displacement is a measure of the plastic separation of the crack faces at the crack tip. It indicates how far the cracks extend under shear conditions.
Physicochemical Mechanism of Action
Crack tip opening displacement measures the plastic separation of the material faces directly at the crack tip. This occurs under shear conditions that plastically deform the material faces and extend the crack further.
Metallurgical Relevance & Welding Risks
High crack tip opening displacement can increase the risk of hot cracking, especially in stiff materials like martensite. This can significantly shorten weld life and cause safety issues in service.
Workshop Practice & Procedures
To ensure low crack tip opening displacement, cooling the weld slowly is important. This can be achieved using cooling water or gas. Rapid cooling can lead to increased crack tip opening displacement and hot cracking.