Strain-induced corrosion cracking of low-alloy steels in LWR-systems — interpretation of susceptibility by means of a three dimensional (T, ϵ, dissolved oxygen) diagram

Stress corrosion cracking susceptibility of a reduced-activation martensitic steel F82H

“…It is reported that low alloy steels become sensitive to the strain-induced corrosion cracking (SICC) at faster strain rate of 1 Â 10 À6 s À1 [19]. A NT-specimen was tested by SSRT at 573 K with a faster strain rate of 1 Â 10 À6 s À1 in oxygenated (DO = 10 ppm) water.…”

Strain-induced corrosion cracking behaviour of low-alloy steels under boiling water reactor conditions

“…Cracking 0022-3115/$ -see front matter Ó 2008 Elsevier B.V. All rights reserved. doi:10.1016/j.jnucmat.2008.06.035 incidents with a major or relevant contribution of SCC to the total crack advance in properly manufactured and heat-treated low-alloy primary pressure boundary components were not observed [1][2][3][4][5][6][7].…”

“…Service experience has thus clearly shown that SICC may occur in C & LAS pressure boundary components in LWRs under unfavourable conditions [1][2][3][4][5][6][7]. Furthermore, laboratory background knowledge [1,6,[16][17][18][19][20] indicates, that the current 'ASME III fatigue design' and 'ASME XI fatigue crack growth evaluation curves' in Sections III and XI of the ASME Boiler and Pressure Vessel Code might be non-conservative for certain ranges of these critical system conditions.…”

“…In BWRs, steam and feedwater piping as well as condensate systems and RPV feedwater nozzles have been affected. In the secondary circuit of pressurized water reactors (PWR), cracking has been observed in feedwater piping/tanks and heat exchangers, feedwater nozzles of PWR steam generators and steam generator girth welds [1][2][3][4][5][6][7].…”

“…The SICC behaviour of C & LAS was mainly characterized by slow strain rate (SSR) [7][8][9][10][11][12][13][14][15] and low-cycle fatigue (LCF) tests [7,[16][17][18][19] with smooth specimens. Based on these tests, critical system conditions for the occurrence of SICC could be established.…”