Page 374 - Mechanical Behavior of Materials
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Section 8.6 Fracture Toughness Values and Trends 375
Figure 8.31 Effect of thickness on fracture toughness of an alloy steel heat treated to the
high strength of σ u = 1720 MPa. (Adapted from [Steigerwald 70]; copyright c ASTM;
reprinted with permission.)
σ , ksi
ο
100 150 200 250 300
200 AISI 4340 Steel 160
K , Fracture Toughness, MPa m 120 120 K Ic
160
ksi in
80
80
40
Ic
0 40
0
800 1200 1600 2000
σ , Yield Strength, MPa
o
Figure 8.32 Fracture toughness vs. yield strength for AISI 4340 steel quenched and tempered
to various strength levels. (Adapted from an illustration courtesy of W. G. Clark, Jr.,
Westinghouse Science and Technology Ctr., Pittsburgh, PA.)
