Inconel Intergranular Corrosion Susceptibility
Inconel intergranular corrosion: Nickel alloys with high carbide content can selectively corrode at grain boundaries. Optimized carbon content and stabilization annealing reduce this risk.
Physical-Chemical Mechanism of Action
Inconel alloys contain nickel, niobium, and other metals with high carbide content. Under certain environmental conditions, these carbides can selectively corrode at the boundaries between different grain sizes. This leads to local weakening and potential cracking.
Metallurgical Relevance & Welding Risks
Intergranular corrosion can impair the mechanical strength of the weld and lead to cracking or wear. This is especially dangerous in high temperatures or aggressive environments. Incorrect carbon content or inadequate stabilization can increase the risk.
Workshop Practice & Action Guidelines
To minimize intergranular corrosion, it is important to precisely control the carbon content in the alloy. For Inconel alloys, an optimal carbon content of about 0.15% should be ensured. Additionally, stabilization annealing should be performed to stabilize the carbides and reduce their susceptibility to selective corrosion.