Fig. 8.15 S-N data for SAE 4340 steel ground with various abrasives. AISI 4340 conditions: quenched and tempered to 50 HRC, surface grinding, cantilever bending, zero mean stress, 75 °C. Source: Ref 14 More

Fig. 6.13 Isothermal transformation diagram for 4340 steel and isothermal heat treatments applied to produce various microstructures for fracture evaluation. Source: Ref 6.16 More

Fig. 6.15 Fracture morphologies of fracture surfaces of 4340 steel CVN specimens heat treated as: (a) oil quenched and tempered at 200 °C (390 °F) and (b) isothermally transformed at 430 °C (810 °F). Source: Ref 6.16 More

Fig. 18.12 Mechanical properties as a function of tempering temperature for 4340 steel tempered for times of 1 h. Ultimate tensile strength (UTS), yield strength (YS), reduction of area (RA), and total elongation (etel) are plotted, and the properties for low-temperature-tempered (LTT More

Fig. 18.26 Engineering stress-strain curves for quenched 4340 steel tempered at various temperatures for 1 h. Courtesy of Young-Kook Lee. Source: Ref 18.31 More

Fig. 18.29 Strain hardening as a function of true strain in quenched 4340 specimens tensile tested after tempering at various temperatures for 1 h. Courtesy of Young-Kook Lee. Source: Ref 18.31 More

Fig. 19.13 Intergranular fracture surface of CVN-tested 4340 steel oil quenched and tempered at 350 °C (660 °F). SEM micrograph. Courtesy of J. Materkowski. Source: Ref 19.41 More

Fig. 19.19 Room temperature CVN energy absorbed for hardened 4340 steel specimens containing either 0.03 or 0.003% P, austenitized at 870 °C (1598 °F), oil quenched, and tempered at temperatures shown for 1 h. Source: Ref 19.49 More

Fig. 19.20 Intergranular fracture of 4340 steel containing 0.03% P and tempered at 400 °C (750 °F). Specimen was broken by impact loading at room temperature. Source: Ref 19.49 More

Fig. 19.21 Flat cleavage facets and microvoids on fracture surface of 4340 steel containing 0.003% P and tempered at 350 °C (662 °F). Specimen was broken by impact loading at room temperature. Source: Ref 19.49 More

Fig. 19.22 Interlath carbides formed during tempering of 4340 steel containing 0.003% P at 350 °C (660 °F). (a) Bright-field image. (b) Dark-field image taken with a cementite diffracted beam. Transmission electron microscope micrographs. Source: Ref 19.49 More

Fig. 19.29 Static fatigue curves for quenched and tempered 4340 notched specimens charged with hydrogen and baked at 150 °C (300 °F) for the times shown. Source: Ref 19.97 More

Fig. 3.21 Microstructure of an AISI/SAE 4340 cast steel gear in the (a) as-cast condition consisting of dendrites of bainite (gray etching constituent) and interdendritic regions of ferrite (light etching constituent) and pearlite (dark etching constituent), (b) carburized condition More

Fig. 10.3 Change in mechanical properties of 4340 steel versus tempering temperature. Source: Ref 10.1 More

Fig. 5.41 Micrographs of a water-quenched AISI/SAE 4340 steel with a fully martensitic microstructure. Micrograph (a) was taken in bright-field illumination, and micrograph (b) was taken with dark-field illumination. Note the clarity of the prior austenite grain boundaries in the dark-field More

Fig. 39 Baking AISI 4340 steel at 300 °F for different times, showing the effect of baking on the incubation of failure More

Fig. 30 Macrograph of AISI 4340 quenched and tempered steel illustrating macroetched pure quench crack. Source: Ref 25 , 36 More

Fig. 11 Changes in the mechanical properties of AISI 4340 steel with tempering temperature. Source: Ref 12 More

Fig. 2.2 Scanning electron fractograph of intergranular SCC in a modified MSI 4340 steel exposed to a saltwater environment. Original magnification: 1800×. Source: Ref 2.17 More

Fig. 3.13 Minimum failure stresses and maximum survival stresses for AISI 4340 steel as affected by degree of biaxiality at various thicknesses. Source: Ref 3.27 More