“…Thao Phuong BUI, 1) Yukio MIYASHITA, 2) * Yasushi MORIKAGE, 3) Tetsuya TAGAWA, 4) Tsunehisa HANDA, 4) Yoshiharu MUTOH 5) and Yuichi OTSUKA 5) ferrite-pearlite structure, 7) networked and distributed pearlite structures, 8) size and spacing of uniformly distributed pearlite particles 9) and hardness of second phase particles 10) on fatigue crack growth behavior had been investigated. These previous studies have revealed that fatigue crack growth resistance in Paris regime is high for (1) the banded ferrite-pearlite steel with narrow pearlite band spacing, (2) distributed pearlite structure compared to networked pearlite structure, (3) larger size and spacing of uniformly distributed pearlite structure, and (4) harder second phase particle.…”