抄録
The effect of aging treatment on fatigue behavior of Nb-added ferritic stainless steel type 429 welds in 3% NaCl solution was investigated. Two filler metals with different chemical compositions, Filler I and II, had been used for the MIG butt welding of type 429. After aging treatment at 700℃ for 100 hours was applied to the smooth specimens of the welds, the fully reversed axial fatigue tests were performed in 3% NaCl solution. In the case of the welds with Filler I, there was almost no change in corrosion fatigue strength even after aging treatment. On the other hand, in the case of the welds with Filler II, the corrosion fatigue strength decreased after aging treatment. It was concluded that the combination of aging treatment and heat history of welding using Filler II caused the sensitization of the base metal of the welds and increased the sensitivity to the corrosive environment.
