中温大気中環境における溶接継手の疲労き裂伝ぱ特性

抄録

Fatigue crack propagation rates of SB450 steel plate were measured at a stress ratio of 0. The fatigue crack propagated through the weld metal or the base metal at room temperature and 300°C in air. In order to perform the high temperature test, a special furnace was made. The furnace achieved the proper distrbution of temperature, which reduced the compressive thermal sterss near the center portion of specimen below 1 MPa. The low thermal stress condition avoided the enhancement of fatigue crack closure. Finally, the same fatigue crack propagation properties were obtained at room temperature and 300°C.