Grain-boundary structure and precipitation in sensitized austenitic stainless steel

Grain-boundary carbide precipitation and intergranular corrosion in sensitized austenite stainless steel were examined by transmission electron microscopy to clarify the effect of grain-boundary structure on precipitation and corrosion. The propensity to intergranular precipitation depends strongly on the grain-boundary structure. Carbide precipitates tend to be detected at grain boundaries with higher Σ values or larger deviation angles (Δθ) from low-Σ coincidence site lattice misorientations. The more ordered boundary requires a longer time for intergranular carbide precipitation and corrosion than less ordered or random boundaries.