| Title |
Microstructural Effects on Crack Initiation Toughness Jic and Crack Growth toughness Tr |
| Authors |
오태성; R . O . Ritchie(Tae Sung Oh) |
| Abstract |
Microstructural effects on crack initiation toughness (J_(IC)) and crack growth toughness (T_R) have been examined for HP9-4-20 steel and ASTM A710 steel. Microstructural changes, which increased the fracture strain (ε_f) and decreased the yield strain (ε_o), improved both J_(IC) and T_R, and had the larger effect on T_R for ASTM A710 steel with law strength. Observation of crack profiles revealed a zig-zag fracture which propagated along the spiral slip lines emanating from the blunted crack tip for ASTM A710 steel, and along the straight slip lines characteristic of a non-blunted crack for HP9-4-20 steel. |