[1K05-07] Corrosion in Water Coolant

[1K06] The effect of thermal aging time and temperature on SCC of SUS630 in high-temperature water

*Takuyo Yamada¹, Takumi Terachi^2,1, Makie Okamoto^3,1, Koji Arioka¹ (1. INSS, 2. KEPCO, 3. Kobe Material Testing Lab.)

Keywords:SUS630, 17-4ph stainless steel, SCC growth behavior in high temperature water, thermal aging, precipitation hadening heat tereatment

The effect of thermal aging time and temperature on SCC of SUS630 in high temperature water were investigated using aging temperature range from 400 to 320 ℃ for time periods up to 20,000h. After thermal aging at 320℃ for 10,000h, the SCC growth rate and the hardnes increased. The fine Cu-rich phase and G phase were detected in the aged at 320℃ for 10,000h material by Atom probe analysis. It is suggested that such as microstructures might affected to the age hardening and SCC behavior.