Grain boundary anisotropy
Grain boundary anisotropy describes that transition zones between crystallites of different orientations can respond differently. This affects creep and corrosion.
Physical-Chemical Mechanism of Action
Grain boundary anisotropy arises from different crystal orientations in a metal. These different orientations lead to different properties at the interfaces between the crystals.
Metallurgical Relevance & Risks in Welding
This anisotropy can affect diffusion-controlled creep behavior, which can lead to long-term deformation. Additionally, it increases the susceptibility to intergranular corrosion, as certain orientations are susceptible to corrosion.
Workshop Practice & Action Guidelines
To minimize grain boundary anisotropy, it is important to ensure a uniform weld. When selecting the material, use crystals with low anisotropy or process the material so that the different orientations are balanced. During cooling, pay attention to a controlled cooling time and temperature to obtain uniform properties throughout the weld.