Identifying the Corrosion Factors

Material Chemical composition of alloy Crystal structure Grain boundary (GB) composition Surface condition 

Environment Chemical definition Circumstance Type, chemistry, concentration, phase, conductivity Velocity, thin layer in equilibrium with relative humidity, wetting and drying, heat transfer boiling, wear and fretting, deposits 

Stress Stress definition Sources of stress Mean stress, maximum stress, minimum stress, constant load/constant strain, strain rate, plane stress/plane strain, modes 1, II, III, biaxial, cyclic frequency, wave shape Intentional, residual, produced by reacted products, thermal cycling 

Geometry Discontinuities as stress intensifiers Creation of galvanic potentials Chemical crevices Gravitational settling of solids Restricted geometry with heat transfer leading to concentration effects Orientation vs. environment 

Temperature At metal surface exposed to environment Change with time 

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