Fig. 7 Optical micrographs of the cup portion showing (a) tempered martensite in the case region, (a) tempered martensite and some ferrite (light) in the core More

Fig. 8 Optical micrographs of failed portion showing (a) tempered martensite in the case region, (a) tempered martensite and some ferrite (light) in the core More

Fig. 3 Structure of the steel after the heat treatment (tempered martensite), etched with Nital. 200 × More

Fig. 8 Microstructure of the new cylinder clamping rod showing tempered martensite structure, 3000× More

Fig. 12 Tempered martensite microstructure of the PH 13-8 Mo stainless steel and transgranular internal crack from the shrink link cylinder wall (Vilella's etchant, ×1000). More

Fig. 9 Micrograph of the shaft microstructure, consisting of tempered martensite. Original magnification 800×; 3.5% nital etch More

Fig. 3 Typical microstructure of the submitted shaft: tempered martensite (nital 3% etch, 800×) More

Fig. 8 (a, b) Inner race; aligned carbides in the matrix of tempered martensite More

Fig. 7 Inclusions and a pipelike cavity in tempered martensite of AISI E4340 steel. (a) Original magnification: 100×. (b) Original magnification: 600×. Courtesy of Mohan Chaudhari, Columbus Metallurgical Services More

Fig. 9 Microstructure of the spindle, showing tempered martensite with some ferrite. Nital etch, 100×. More

Fig. 7 Representative microstructures (quenched and tempered martensite) of the cap screws. Nital etch. (a) 126×. (b) 504×. More

Fig. 2 Microstructure of the tie rod. Tempered martensite with spheroidized carbide. 250×. More

Fig. 8 Microstructure of “representative” P-110 tempered martensite. 324× More

Fig. 12 Fine, tempered martensite observed in core. Compare with coarse, untempered martensite in Fig. 11 . 2% nital etch. 315×. More

Fig. 11 Microstructure opposite weld joint. Structure is tempered martensite. 5% nital etch. 1000×. More

Fig. 5 Higher magnification view showing tempered martensite, sulfide stringer inclusions and carbide networking. 315×. More

Fig. 11 Gear core microstructure consisting of tempered martensite with an average hardness of 24 HRC. Nital etchant. (a)154×. (b)616× More

Fig. 6 Microstructure of region A in Fig. 5 , consisting of tempered martensite and ferrite. Nital etch. (a) 268×. (b) 610× More

Fig. 7 Representative micrograph of microstructure showing tempered martensite. 1% nital. 1000× More

Fig. 8 Representative tempered martensite microstructure of the pitch horn bolt. 245× More