Intergranular corrosion

The intergranular corrosion ( IC) is a form of corrosion that can occur in most alloys at corresponding conditions. It is also called " grain disintegration ". The corrosion takes place along the grain boundaries.

When alloyed with chrome steels, the chromium contained in the connecting material by heating (for example in welding ), with the carbon to form chromium carbide (). This makes the chrome is no longer for corrosion protection ( formation of a passive layer) in the heated area. This occurs particularly in carbon -rich steels.

With corrosion-resistant steels, the binding of carbon by niobium or titanium to niobium or titanium carbide ( stabilized steels) or the reduction of the carbon content ( IF steel, or LCS = low carbon steel or ELC = extra low carbon acts carbon content ≤ 0, 03 %) of the IK contrary: These measures prevent the harmful reduction of the chromium content along the grain boundaries.

• Corrosion