Fig. 18 AISI O1 tool steel that cracked during oil quenching. Note the cracks emanating from the sharp corners. The four holes, which are close to the edge, also contribute to cracking. Source: Ref 16 More

Fig. 11.2 Quench cracks formed in oil-quenched tool steel die. Cracks originated from the sharp corners of the keyway and from holes that were located too close to the surface. More

Fig. 16 Examples of quench cracks. (a) Micrograph of AISI 4340 quenched and tempered steel illustrating a macroetched pure quench crack. (b) Micrograph of AISI 4142 steel as-quenched and tempered. The microstructure is tempered martensite with quench cracking at the fillet radius. Original More

Fig. 11.17 Microstructure of quench crack. The crack follows the former austenite grain boundaries. More

Fig. 10.59 Quenching crack susceptibility as a function of the “equivalent carbon” used as a measure for hardenability. Source: Ref 13 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. 10.5 Impingement of martensite plates leading to quench cracks (QC) More

Fig. 24 Quench crack with typical geometry More

Fig. 7 Relationship between quench cracking frequency and martensite start (M s ) temperature. Source: Ref 8 More

Fig. 8 Relationship between quench cracking frequency and austenitic grain size. Source: Ref 8 More

Fig. 9 Relationship between carbon equivalent (C eq ) and quench cracking frequency. Source: Ref 8 More

Fig. 20 Design solutions to the quench-cracking problem often encountered in shaft hardening over a cross hole. Source: Ref 19 More

Fig. 27 Two forms of quench cracking. Source: Ref 32 More

Fig. 22 Quench crack in flyweight More

Fig. 25 Quench crack promoted by the presence of a deep, sharp stamp mark in a die made of AISI S7 tool steel. Source: Ref 16 More

Fig. 26 A 4140 grade steel seamless tubing that failed because of quench cracks. (a) Cross section of tube showing extensive cracking revealed by dye-penetrant inspection. (b) SEM micrograph showing intergranular fracture at a crack origin. Original magnification: 90×. (c) SEM micrograph More

Fig. 35 Schematic of quench crack formation. Source: Ref 19 More

Fig. 9.8 Quench cracks in axle shaft flange radius. Source: Ref 4 More

Fig. 9.9 Quench crack in induction-hardened shoulder. Source: Ref 4 More

Fig. 9.10 Quench crack at spline end of axle shaft. Source: Ref 4 More