Ductility
Ductility is the ability of a material to deform plastically without breaking. This occurs through elongation of the crystal planes. High ductility leads to low fracture strength.
Physicochemical Mechanism of Action
Ductility describes a material's ability to deform plastically under load without cracking. This happens through the elongation of the crystal lattice planes in the material. With high ductility, the crystals can adjust and stretch, which improves stress absorption.
Metallurgical Relevance & Risks in Welding
High ductility is generally desirable because it protects the material from fracture. However, too much ductility can also have negative effects: it leads to low fracture strength and can cause the weld to deform plastically under high stress without breaking. This can result in unwanted distortion or insufficient strength in the weld zone.
Workshop Practice & Action Items
To make the best use of a material's ductility, it's important to choose the right welding process and parameters. This can be influenced, for example, by selecting the right shielding gas or the correct voltage in TIG welding. With highly ductile steel, it's important to cool slowly after welding (t8/5 > 25 s) to coarsen the grain structure and increase toughness.