Lamellar Tearing
A lamellar tear is a step-like crack in rolled metal parallel to the plate surface, caused by high tensile stresses in the thickness direction. Non-metallic stringer segregations promote this crack.
Physicochemical Mechanism of Action
Lamellar tearing forms in rolled metal when it is subjected to high through-thickness tensile stresses. These stresses arise from shrinkage of the material during cooling. Non-metallic stringers such as oxygen or hydrogen can amplify these stresses and promote the crack formation field.
Metallurgical Relevance & Welding Risks
Lamellar tearing can lead to severe hardening and cracking, especially near the weld seam. This can significantly impair the mechanical strength of the component and cause premature failure. It is particularly dangerous in metals with high oxygen content or when deoxidizing agents are used.
Workshop Practice & Action Guidelines
To prevent lamellar tearing, the metal should be preheated well before welding to reduce stresses. Thorough cleaning and removal of non-metallic inclusions is essential. In severe cases, mechanical drawing or special treatment with a lamellar tearing prevention method can be applied.