Effect of Externally Added Molybdate on Repassivation and Stress Corrosion Cracking of Type 304 Stainless Steel in Hydrochloric Acid

Synthesis and evaluation of corrosion resistance of molybdate-based conversion coatings on electroplated zinc

“…Moreover, it is indicated that the role of MO 4 2− and O 2 is the healing and repair of defects in the air-formed oxide. Devasenapathi et al [20] propose that a further mechanism of corrosion inhibition by molybdate species may be due to its ability to react with chloride according to:…”

Inhibition of localized corrosion in chromium containing stainless alloys

“…It is detected throughout the fi lm as Mo 4 + , Mo 5 + , and Mo 6 + (Yashiro et al, 1997). It has also been found as Mo 3 + and Mo 4 + in the inner layers (Devasenapathi & Raja, 1996). MoO 4 2-suppresses both pit initiation and growth in 20Cr-25Ni-xMo SS in NaCl solutions (Sugimoto & Sawada, 1976).…”

“…Photoinhibition of pitting corrosion by UV illumination is attributed to the modifi cation of the passive fi lm, the electric fi eld in the fi lm, and changes in the electronic structure on the fi lm/solution interface (Fujimoto et al, 1998;MacDonald & Heaney, 2000;MacDonald et al, 1996). , has shown a detrimental effect on the repassivation of 304 SS in 1 m HCl when present in low concentrations (Devasenapathi & Raja, 1996). This was attributed to an increase in the cathodic reaction rate and a consequent increase in anodic dissolution.…”

“…The deposition of the reduction products (Cr 2 O 3 and MoO 2 ) is also proposed as an inhibiting mechanism. Cr 3 + and Mo 4 + may be built into the fi lm (Devasenapathi & Raja, 1996;Gluszek et al, 1985;Sugimoto & Sawada, 1976;Zuo et al, 2002).…”

Electron Spectroscopy for Chemical Analysis Study of Corrosion Films Formed on Manganese Stainless Steels

“…The films formed in hydrochloric acid (HCl) were analyzed since earlier SCC studies were carried out in this solution, which provides an active condition. 2,4,8 While literature on the passive films formed on high Mn-containing stainless steels is sparse, passive films formed on ferritic (Fe-Cr) and austenitic (Fe-Cr-Ni) stainless steels have been investigated widely. [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] The rich Cr content of the passive films formed on these stainless steels in HCl, [9][10][11] sulfuric acid (H 2 SO 4 ), [12][13][14][15] and other neutral environments [16][17][18] was the primary reason for the excellent resistance exhibited by these alloys.…”