Verschillende vormen van corrosie bij inox

• General or Uniform Corrosion. This is not really a category, but corrosion can indeed occur uniformly or locally. If the contamination is uniform over the entire surface, this is often due to incorrect material choice, such as using AISI 304 in a polluted environment where AISI 316 would have been better. For outdoor use, we systematically recommend using AISI 316, although in certain less polluted areas, AISI 304 might suffice. However, we do not settle for 'a 75% chance that there will be no problems...' Very often, corrosion also occurs under the influence of external contaminants: the piece is still completely intact, but steel particles from the outside settle on the piece and start to rust.

• Local Corrosion, this is usually more dangerous than general corrosion. It often has a cause in one of the following forms of corrosion. Once corrosion starts, it can progress quickly and cause the piece to rust through rapidly.

• Galvanic Corrosion. Due to the use of different materials together, such as aluminum with stainless steel. Depending on the circumstances, the 'weaker' or 'less noble metal,' in this case, the aluminum, will fail. Circumstances (outdoor or indoor, aggressive or not) play a significant role here.

• Pitting Corrosion. Circumstances cause the passivation layer to be broken and not restored, for example, by damage, contamination, chlorine, ... Once started, the corrosion process progresses quickly.

• Crevice Corrosion. The name says it all: corrosion that occurs in crevices. Due to the lack of oxygen in the crevice, the self-healing passivation layer can form with difficulty. This must be considered during design (flange connections) and in the welding phase. In cases with increased risk, there should be no hesitation, and through welding or double-sided welding without many craters should be done.

• Intergranular Corrosion. Circumstances (such as heating) have caused the chromium content to drop below 10.5%, the minimum limit necessary for forming a passivation layer. Without a tight passivation layer, there is no sufficient corrosion resistance...

• Stress Corrosion. Finally, erosion of the material; this is not really corrosion in the sense of the word that we usually know it, namely rust formation. However, in certain circumstances, such as tanks, time and used conditions cause the material to wear away.

This was a brief listing of all the different types of corrosion, but do not be alarmed by this list. They exist, but with normal use and good design, we see very few problems in practice.