Fig. 8.4 Various types of intergranular corrosion. (a) Interdendritic corrosion in a cast structure. (b) Interfragmentary corrosion in a wrought, unrecrystallized structure. (c) Intergranular corrosion in a recrystallized wrought structure. All etched with Keller’s reagent. Original More

Fig. 1 Various types of intergranular corrosion. (a) Interdendritic corrosion in a cast structure. (b) Interfragmentary corrosion in a wrought, unrecrystallized structure. (c) Intergranluar corrosion in a recrystallized wrought structure. All etched with Keller’s reagent. 500× More

Fig. 13.8 Intergranular corrosion produced by sensitizing a 410 steel on tempering. Corrosion test: 14 days in 20% salt fog. Source: Ref 13.8 . Copyright: NACE International, 1953 More

Fig. 18.10 Intergranular corrosion of stainless steel. Source: Ref 5 More

Fig. 18.12 Intergranular corrosion in sensitized type 304 stainless steel. Original magnification 100× More

Fig. 45 Intergranular corrosion of sensitized HAZ grain boundaries and methods for its prevention. The four different panels were joined by welding and then exposed to a hot solution of nitric-hydrofluoric acid (HNO 3 -HF). Weld decay, such as that shown in the type 304 steel (bottom right More

Fig. 3 Planar (a) and cross-sectional (b) views of intergranular corrosion (grain dropping) in a sensitized austenitic stainless steel. As-polished. (a) 50×. (b) 100×. Courtesy of G.F. Vander Voort, Carpenter Technology Corporation More

Fig. 39 Intergranular corrosion of a contaminated E-Brite ferritic stainless steel weld. Electrolytically etched with 10% oxalic acid. 200× More

Fig. 40 Intergranular corrosion of the inside surface heat-affected zone of E-Brite stainless steel adjacent to the weld fusion line. Electrolytically etched with 10% oxalic acid. 100× More

Fig. 5 Intergranular corrosion of a type 304L stainless steel tube in a shuttle orbiter ammonia boiler. (a) Test performed to show tube ductility. 1×. (b) Cross section through the thin-wall (0.2 mm, or 8 mils) tube revealing sensitization on outside diameter due to carbonaceous deposit formed More

Fig. 14.6 Strain-assisted intergranular corrosion attack in alloy HR3C after testing at 600 °C (1110 °F) for 250 h in CO-32H 2 -4CO 2 -0.2H 2 S with (a) 1.3% strain and (b) 2% strain. Corrosion products formed on the metal surface were also observed. Note: the tested specimen surface More

Fig. 14.7 Scanning electron backscattered images showing intergranular corrosion penetration along with the x-ray maps for Cr, O, and S for alloy HR3C after testing at 600 °C (1110 °F) for 1810 h in CO-32H 2 -4CO 2 -0.2H 2 S with 2.2% strain. Source: Ref 7 More

Fig. 10 Intergranular corrosion of stainless steel. Source: Ref 6 More

Fig. 12 Intergranular corrosion in type 304 stainless steel. Original magnification: 100×. Source: Ref 3 More

Fig. 7.51 Interface profile of intergranular corrosion when the precipitate phase is anodic to the matrix phase. (a) Preferential corrosion of continuous AB 2 phase. (b) Preferential corrosion of discontinuous DE 3 phase More

Fig. 7.52 Interface profile of intergranular corrosion when solute-depleted zone is anodic to precipitate and undepleted matrix. (a) Intergranular attack when precipitate and solute-depleted zone is continuous. (b) Intergranular attack when precipitate and depleted zones are discontinuous More

Fig. 7.55 Effect of carbon content on susceptibility to intergranular corrosion of 18 wt% Cr-10 wt% Ni stainless steels in boiling acidified copper sulfate. Open circle, no corrosion; solid circle, intergranular corrosion. (a) 0.050% C, 18.22% Cr, 10.95% Ni, 0.049% N. (b) 0.027% C, 18.35% Cr More

Fig. 7.56 Time-temperature-sensitization curves for intergranular corrosion of type 347 stainless steel in boiling 65% nitric acid. mpy, mils per year. Source: Ref 85 More

Fig. 7.57 Effect of carbon and nickel content on intergranular corrosion penetration rate of 18 wt% Cr-base stainless steels. Alloys sensitized for 100 h at 550 °C. Immersion in boiling 65% nitric acid. Pds., periods (48 h) of exposure. Redrawn from Ref 84 More