Intergranular corrosion

Intergranular corrosion is a significant phenomenon in surface engineering that specifically affects metallic materials. This corrosion process occurs at the boundaries between the crystal grains of a metallic material and can significantly affect the structural integrity and performance of the material.

The origin of intergranular corrosion often lies in the sensitization of materials, especially alloys such as stainless steel. Sensitization occurs when certain alloying elements, such as chromium, leach out of the matrix of the material and react at the grain boundaries. This leads to the formation of chromium carbides, which destroy the protective passivation layer at the grain boundaries and make the material more susceptible to corrosion.

In surface technology, the prevention of intercrystalline corrosion is of crucial importance. This can be achieved through suitable alloy compositions, heat treatments or the use of corrosion-resistant coatings. Preventing sensitization is a key aspect in the manufacture of components and surfaces that are used in environments with potentially corrosive influences.

Testing for intercrystalline corrosion is an important step in the quality assurance of metallic components. Techniques such as the Huey test or the Straus test are used to check the susceptibility of materials to this form of corrosion. The knowledge and targeted treatment of intercrystalline corrosion in surface technology are therefore of crucial importance in order to guarantee the durability and reliability of metallic materials.