SA508 Gr3 Cl2 저합금강과 용접부의 290℃ 수화학 환경에서 피로균열거동 분석

The fatigue crack growth behaviors of SA508 Gr.3 Cl.2 low alloy steel in high temperature water enviromment were investigated. Overall, weld metal showed similar crack growth rate as that of base metal. At 0.01 Hz, fatigue crack growth rate (FCGR) was higher than that in air while the difference was smaller at 0.1Hz. Also, FCGR showed △K dependency at 0.1 Hz only, indicating that the environmental effect was much greater at slower loading frequency of 0.01 Hz. FCGR of SA508 Gr.3 Cl.2 low alloy steel was compatible to or smaller than the ASME Sec. XI fatigue reference curves in high temperature water environment.