Corrosion scientist, LaQue Center for Corrosion Technology, Inc., Wrightsville Beach, NC
Pages: 17 Published: Jan 1990
Crevice corrosion behavior for a series of austenitic and duplex stainless alloys was determined in a number of simple solutions as well as in diluted natural seawater containing up to 10 g/L Cl- and 10 g/L SO4=. Remote crevice assembly technology using zero resistance ammeters revealed differences in initiation and propagation resistance. Effects of solutionion concentration, alloy composition and the influence of crevice geometry and biological activity are discussed.
While S30400 and S31600 were found to be susceptible in all tests considered, other materials (N08904 and S32550), and especially a 6% molybdenum alloy (S31254), were substantially more resistant. Test results indicate some beneficial effects of sulfate at lower levels of chloride. However, at high chloride levels, high sulfate appears detrimental. At comparable chloride levels crevice corrosion was more severe in diluted natural seawater than in synthetic solutions.
This work is part of an on-going study involving additional alloys and more varied water chemistries. The ultimate goal of this research is the preparation of a Crevice Corrosion Atlas for Stainless Steel in Waters.
stainless steels, crevice corrosion, diluted natural seawater, chloride/sulfate, remote crevice assembly, initiation resistance, propagation resistance, crevice geometry, biological influence
Paper ID: STP26100S