Microstructural corrosion
Structural corrosion is a specific corrosion process that attacks particular microstructural constituents or inclusions within the metal. It leads to local wear spots and can severely impair mechanical strength.
Physical-Chemical Mechanism of Action
Localized corrosion occurs when certain chemical conditions or special metal structures (like inclusions or phase transformations) create weak spots in the metal matrix. At these spots, the metal reacts with the corrodent and forms corrosion products that eat away the material.
Metallurgical Relevance & Welding Risks
Localized corrosion can show up after welding when special microstructures or inclusions in the weld pool aren't handled right. It leads to local wear points and can really hurt the mechanical strength of the weld, which can cause cracks and breaks.
Shop Practice & How-To
To avoid localized corrosion, make sure the metal is cleaned properly before welding. Use high-quality shielding gases and pay attention to proper cooling after welding. For special metals or microstructures, extra pretreatment may be needed to prevent corrosion.