Fig. 12.5 Because atoms at grain boundaries are in a higher energy state, the grain boundaries become anodic. More

Fig. 2.22 Grain boundaries in equilibrium. Source: Ref 2 More

Fig. 18.11 Precipitation of chromium carbide at grain boundaries More

Fig. 2 Nature of grain boundaries More

Fig. 9 Depletion of chromium from the austenite near grain boundaries due to chromium carbide precipitation. Source: Ref 14 More

Fig. 2.27 Grain boundaries act as barriers to slip by dislocations. Source: Ref 2.1 More

Fig. 5 Schematic diagram of grain boundaries in a metal More

Fig. 6 Ferrite grains and grain boundaries in a low-carbon ferritic sheet steel etched with 2% nital. 300× 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. 4.17 Proeutectoid cementite (white network) formed at austenite grain boundaries in an Fe-1.22C alloy held at 780 °C (1435 °F) for 30 min. Dark patches are pearlite colonies and the remainder of the microstructure is martensite and retained austenite. Nital etch. Original magnification More

Fig. 8.4 Prior-austenite grain boundaries in the core of a carburized steel. (a) Etched and partially repolished, leaving remnants of intragranular structure. (b) Etched and repolished to remove all intragranular structure. Light micrographs; details of etching are given in the text. Source More

Fig. 13.3 (a) Carbide network at prior austenite grain boundaries in 52100 steel. Light micrograph, nital etch, original magnification 600×; shown here at 75%. (b) Fracture along grain-boundary carbides in 52100 steel. Scanning electron micrograph, original magnification 415×; shown here at 75 More

Fig. 8.28 Prior austenite grain boundaries in a quenched 0.5% Mo-B steel. (a) 200× and (b) 500×. Boiling alkaline sodium picrate etch followed by 10 seconds in 2% nital etch and 20 seconds in 4% picral etch More

Fig. 8.29 Prior austenite grain boundaries in a quenched and tempered MIL-S-23194 composition F-steel forging. Modified Winsteard’s etch. 500× More

Fig. 8.46 Annealed AISI/SAE 316 austenitic stainless steel showing grain boundaries but the absence of twins. Ideal for grain size measurements by image analysis. Electrolytically etched with 60% nitric acid and 40% water using a platinum cathode at 5 V. 500× More

Fig. 10.62 Quench crack in prior austenitic grain boundaries. During heating for quenching there was excessive austenitic grain growth. Etchant: nital 2%. Courtesy of M.M. Souza, Neumayer-Tekfor, Jundiaí, Brazil. More

Fig. 16.5 Crack following prior austenitic grain boundaries in AISI 410 steel subjected to corrosion testing according to NACE TM 0177 standard. Courtesy of A. Zeemann, Tecmetal, Rio de Janeiro, Brazil. More

Fig. 59 Intergranular oxidation of the surface along prior grain boundaries in a carburized steel. Original magnification: 1000×. Source: Ref 78 More

Fig. 11 Ferrite vein crack occurring in the prior-austenite grain boundaries of weld metal deposited on A709-grade 50W More

Fig. 55 Creep cavities and creep wedges forming at grain boundaries More