The Effect of Microchemistry on the Crack Response of Lightly Cold Worked Dual Certified Type 304/304L Stainless Steel After Sensitizing Heat Treatment
Sensitization and deformation have previously been implicated in the stress corrosion cracking (SCC) susceptibility of Type 304 stainless steel (SS) in oxygenated water. However, Type 304L SS, with reduced carbon content, is expected to be resistant to sensitization effects. The current work evaluates the SCC response of two dual certified Type 304/304L SSs after a sensitization heat treatment. It is shown that other material factors, namely boron content and delta ferrite stringers, can lead to sensitization and subsequent SCC even in L-grade materials.
KeywordsStress corrosion cracking Boron Delta ferrite Cold work 304 SS 304L SS
The authors would like to thank the Rickover Fellowship Program in Nuclear Engineering sponsored by the Naval Reactors Division of the U.S. Department of Energy in conjunction with Bettis Laboratory, West Mifflin, PA for funding this research. The authors would also like to thank the Michigan Center for Materials Characterization for use of the instruments and staff assistance.
- 2.R. Otterberg, W. Roberts, Intergranular precipitation in type 304 L austenitic stainless steels containing small amounts of boron, in Processing of Stainless Steel (1985), pp. 229–239Google Scholar
- 3.B.D. Miller, M.G. Burke, Characterization of type 304L stainless steel: comparison of ASTM A262 practice A and analytical electron microscopy techniques, in 15th International Conference on Environmental Degradation of Materials in Nuclear Power Systems-Water Reactors (2012)Google Scholar
- 4.E.C. Johns, B.D. Miller, Effects of boron and mechanical processing on intergranular attack in dual certified type 304 stainless steel determined using DL-EPR, in 16th International Conference on Environmental Degradation of Materials in Nuclear Power Systems—Water Reactors, Asheville, NC (2013)Google Scholar
- 5.K.B. Fisher, B.D. Miller, E.C. Johns, R.H. Hermer, C.M. Brown, E.A. Marquis, The effect of cold work on the crack response of dual certified type 304/304L stainless steel containing boron, in 17th International Conference on Environmental Degradation of Materials in Nuclear Power Systems—Water Reactors (2015), pp. 1–17Google Scholar
- 6.ASTM, Standard practices for detecting susceptibility to intergranular attack in austenitic stainless steels, in A262 (2014), pp. 1–20Google Scholar
- 8.W. Mills, Critical review of fatigue crack growth rates for stainless steel in deaerated water–parts 1 and 2, in Presentation to EPRI PWR Materials Reliability Program Conference, Colorado Springs, CO (2010)Google Scholar
- 9.E. Bain, R. Aborn, J. Rutherford, The nature and prevention of intergranular corrosion in austenitic stainless steels. Trans. Am. Soc. Steel Treat. 21(1), 481–509 (1933)Google Scholar