Stress corrosion cracking growth tests of small compact tension specimens with different pre-crack length in high temperature water containing hydrogen peroxide

Nakano, Junichi; Sato, Tomonori; Kato, Chiaki; Kaji, Yoshiyuki; Yamamoto, Masahiro; Tsukada, Takashi; Iwata, Yusuke*; Tomota, Yo*

no journal, , 

Hydrogen peroxide (HO) is produced by water radiolysis. To study effects of HO environments on SCC behavior of stainless steel, crack growth test was conducted in high temperature water containing HO. Two types of 0.25T-compact tension (CT) specimens were prepared from thermally sensitized type 304 stainless steel. After fatigue pre-crack length of 4.4-4.8 mm introduction, the pre-crack was shortened to 1.1-1.7 mm. For the CT specimens with long pre-crack length, intergranular SCC (IGSCC) was observed near side grooves. For the CT specimens with shortened pre-crack length, IGSCC area spread to the central region. SCC grew linearly in HO environments although SCC growth in O environments branched off. As outer oxide layer on the pre-crack, FeO was observed in O environments. In HO environments, it changed from FeO toward the crack tip to FeO.