Intergranular stress corrosion cracking sensitized

Intergranular stress-corrosion cracking (IG-SCC) can occur in some sensitized materials when placed under tensile stress. Thus DL-EPR has been used to study the effects of aging time on the susceptibility of Alloy 600 to IGSCC, as shown in Fig. 41 (39). This work also shows the need to modify the experimental parameters of the test to achieve optimal correlation for alloys other than Type 304SS, in this case lowering the KCNS concentration and the temperature while raising the peak potential and the scan rate. 

As a second example, we show in Fig. 27 the nucleation of intergranular stress corrosion cracks in sensitized Type 304SS as observed by Diercks and Dragel at the Argonne National Laboratory (see [56]). The cracks were found to nucleate from pits or at intergranular penetrations (e.g., intergranular attack, IGA). In other cases, cracks are found to nucleate from MnS inclusion but, in this case too, the primary event is probably the formation of a pit which acts as a stress riser. Examination of many micrographs indicates that the critical nucleus is of the order of 30-1 (X) pm deep. 

T.M. Devine and B.J. Drummond, Use of Accelerated Intergranular Corrosion Tests and Pitting Corrosion Tests to Detect Sensitization and Susceptibility to Intergranular Stress Corrosion Cracking in High Temperature Water of Duplex 308 Stainless Steel, Corrosion, Vol 37, 1981, p 104-115... 

M. Hishida and H. Nakada, Critical Cooling Rate of 18Cr-8Ni Stainless Steel for Sensitization and Subsequent Intergranular Stress Corrosion Cracking, Corrosion, Vol 34, 1978, p 338-344... 

S. Zhang, T. Shibata, T. Hamna, Inhibition effect of metal cations to intergranular stress corrosion cracking of sensitized type 304 stainless steel, Corros. Sci. 47 (2005) 1049-1061. 

Wells, D.B., Stewart, J., Davidson, R. et al (1992) The mechanism of intergranular stress-corrosion cracking of sensitized austenitic stainless-steel in dilute thiosulfate solution. Corrosion Science, 33, 39-71. 

It must be remembered that grinding is not allowed on austenitic stainless steel since it may sensitize the steel to intergranular stress corrosion cracking and transform metastable austenite into brittle martensite (see Sect. 14.2.2). 

The extensive IGSCC (intergranular stress corrosion cracking) of sensitized Type 304 SS observed in Boiling Water Reactor (BWR) primary coolant circuits over the past three decades has prompted examination of the stress corrosion cracking of possible stmctural... 

WSRC, WSRC-TR-90-471, "Intergranular Stress Corrosion Cracking A Rationalization of Apparent Differences Among Stress Corrosion Cracking Tendencies for Sensitized Regions in the Process Water Piping and in the Tanks of SRS Reactors," September 28, 1990. 

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