Corrosionsensitive

Corrosionsensitive describes a property of a material, component, or system that makes it susceptible to corrosion under expected service conditions. The term can be written as corrosion-sensitive or, less commonly, as a single word. It encompasses a material’s tendency to undergo electrochemical or chemical degradation, including uniform corrosion, pitting, crevice corrosion, or stress corrosion cracking, given its environment and operating parameters.

Several factors influence corrosion sensitivity. Material composition and microstructure determine how a metal responds to corrosive species, while surface finish and protective coatings affect film stability and barrier quality. The exposure environment—chloride content, humidity, temperature, and pH—plays a critical role, as does the presence of protective oxide films or inhibitors. For example, carbon steels are generally more corrosion-prone in moist, saline environments than stainless steels with a stable passive layer, whereas certain aluminum alloys rely on oxide films that can be compromised under specific conditions.

Assessment of corrosion sensitivity typically involves measuring or estimating corrosion rate and susceptibility to localized forms such as pitting or crevice corrosion. Methods include weight-loss measurements and electrochemical techniques (open-circuit potential, polarization resistance, impedance spectroscopy). Standards and guidelines from organizations such as ASTM and ISO provide methods for comparing corrosion sensitivity across materials and coatings.

Mitigation strategies seek to reduce corrosion sensitivity through material selection, surface treatment, protective coatings, passivation, corrosion inhibitors, and cathodic protection. Design choices that minimize crevices, differential aeration, and moisture accumulation also enhance resistance. Maintaining favorable exposure conditions and regular inspection further reduces the effective corrosion sensitivity of assets.

Understanding corrosion sensitivity is critical in fields such as construction, maritime engineering, energy, and chemical processing, where corrosion can affect safety, performance, and life-cycle costs.