Aspects of Testing and Selecting Stainless Steels for Seawater Applications

Effect of halide anions and temperature on initiation of pitting in Cr–Mn–N and Cr–Ni steels

“…[12][13][14][15][16][17][18] These investigations have usually been performed in chloride solutions with concentrations above the critical value and it has been reported that a temperature increase reduces the protective properties of the passive films owing to the increased reactivity of the chloride ions. [13][14][15][16][17][18] Critical concentrations of aggressive ions [18][19][20] as well as the effects of temperature 20,21 have been reported for chloride solutions.…”

Failure of a super duplex stainless steel reaction vessel

“…For example, Wallen et al [17] found 45-50 C for gas tungsten arc welds and 45-62 C for SMAW welds. On the other hand, Steinsmo et al [18] report values as low as 32 C. We conclude that the failed welds in the VCM Stripper have a lower resistance to localised corrosion than the parent material, but that the localised corrosion resistance was as good as could reasonably be expected for welded S32750. It is also important to note that the CPT test does not directly assess SCC resistance.…”

Crevice corrosion

“…In contrast, in full-immersion tests in seawater, the ratio can be quite high (e.g., 300:1). [100] The remote crevice assembly simulates a real crevice where the crevice-free sample acts as a net cathode and the crevice sample as the net anode. As with any test method based on zero-resistance amperometry (ZRA), both the magnitude and the direction of the current flow carry information about the corrosion process.…”