Relationship between Fracture Toughness JIC and Microroughness Measured on the Fracture Surfaces
오태성 Tae Sung Oh
Abstract
Correlations of the critical fracture strain ε_f and the fracture toughness J_(lc) with the microroughness measured on the fracture surfaces have been investigated for HP9-4-20 steel and ASTM A710 steel with different strength level. The critical fracture strain ε_f was proportional to the local microroughness (1/3)·ln(M²/3f_p) measured on the fracture surfaces. Fracture toughness J_(lc) was in good agreement with (σ_o/3)·ln(M²/3f_p)·l_o and could be estimated using the microroughness parameter M, the characteristic distance l_o, and the effective yield stress σ_o.