Effects of Gamma-Ray Irradiation and Sodium Sulfate on the IGSCC Susceptibility of Sensitized Type 304 Stainless Steel in High-Temperature Water

Abstract

The effects of gamma-ray irradiation and sodium sulfate as an aqueous impurity on the intergranular stress corrosion cracking (IGSCC) susceptibility of sensitized type 304 (UNSI' ) S30400) stainless steel (SS) were studied through slow strain rate tests (SSRT) and corrosion potential measurements in high-temperature water that simulated the BWR normal water chemistry (NWC) and hydrogen water chemistry (HWC) conditions. The SSRT results demonstrated that IGSCC was accelerated by gamma-ray irradiation under the NWC condition, while it was suppressed under the HWC condition. These different effects are attributable to the radiation-induced corrosion potential shifts in the opposite directions depending on the water chemistry condition. When the sodium sulfate was injected up to 0.32 p.S/cm of conductivity, IGSCC was observed even under the HWC condition, but it was suppressed by gamma-ray irradiation.

Electrochemical behaviour of gold and stainless steel under proton irradiation and active RedOx couples

“…A literature review [1][2][3][4][5][6][7][8][9][10]12] shows that the present investigation provides the first data on the evolution of the free exchange potential of AISI 316L/Na 2 SO 4 (0.1 M) interfaces under 6 MeV proton irradiation for dose rates ranging from 8 × 10 6 to 4.8 × 10 7 Gy h −1 . The free exchange potential shows several stages of evolution depending on the dose accumulated by the AISI 316L/Na 2 SO 4 (0.1 M) interfaces.…”

“…The gamma sources that are generally used are 60 Co and the dose rates vary typically in the range 10 3 < dr(Gy h −1 ) < 10 4 . A number of authors report that gamma irradiation shifts the free exchange potential of stainless steels (AISI 304L, AISI 316L and AISI 347) in the anodic direction [1][2][3][4][5]. The free corrosion potential is reported to reach a quasi-steady state in most cases.…”

“…Most of the in situ experiments on corrosion under irradiation that are reported in the literature concern the response of electrodes immersed in electrochemical cells irradiated by gamma [1][2][3][4][5][6][7][8]. The gamma sources that are generally used are 60 Co and the dose rates vary typically in the range 10 3 < dr(Gy h −1 ) < 10 4 .…”

Intergranular stress corrosion cracking initiation model of austenite stainless steels used in BWRs for optimized water chemistry control

“…[15] Ref. [17] SSRT Figure 6. Relationship between failure time and carbon content in sensitized heat-treated materials.…”

“…When γ -rays dose rate is 4 × 10 4 Gy/h, f(γ ,n) is about 2 [15][16][17]. In Figure 6, the IGSCC acceleration ratio was given as follows:…”