Pitting and crevice corrosion susceptibility of super austenitic stainless steels in sea water.

摘要

Pitting and crevice corrosion susceptibility of someudsuper austenitic stainless steels in- sea water were determine element to improve the resistance to pittinguddetermined by field tests and laboratory examinations · (5 6 7)udand analysis. This paper reports the observed corrosion and crevice corrosion . Streicher (l 0) has alsoudsusceptibility behaviour of the tubes' alloys. The inner observed that the combined addition of molybdenum,udsurfaces of the steel tubes were expo$ed to flowing sea nitrogen and silicon provided effective corrosionudwater a specially designed tests rig. The steam c:b.amber resistance behaviour to type 3 I 6 stainless steels.udpart of the rig which was subjected to elevatedudtemperature was the region where the middle portion ofud·the tubes were located. After splitting in theudlaboratory, the tubes from the field test were examinedudwith optical macro-/microscope (Wild M3C Model) andudthe scanning electron microscopy (S. E. M.). Analysisudof the corrosion deposit was performed with the S. E.udM. equipped with Energy Dispersive X -ray (EDAX)udspectrometer, and the X -ray Diffraction spectroscopyud(XRD)_. Thoz1e.h all !!:~~!Joys, except the 3161., wereudfound to be generally corrosion resistant substantial ·ud.... .. . . . - ' ' crevice corrosion occurred ·under the strongly adherentudcalcareous layers deposited in the steam chamberudportion of the tubes as observed in one of the runs