Comparison of the effects of alloyed molybdenum and aqueous molybdate on the pitting resistance of iron-chromium alloys. Final technical report

Technical Report · Tue Jan 01 04:00:00 EST 1985

OSTI ID:5821267

Wistrom, R E; Duquette, D J

Electrochemical techniques were employed to compare and contrast the roles of alloyed Mo and aqueous MoO/sub 4//sup 2 -/ in enhancing pitting resistance of ferritic stainless steels in neutral chloride solutions at 80/sup 0/C. Results indicate that alloyed Mo inhibits pitting in 0.14N and 1N chloride solutions while aqueous MoO/sub 4//sup 2 -/ inhibits in the dilute Cl/sup -/ solution only. Prepassivation experiments show that the major role of high Cl/sup -/ concentrations is to prevent MoO/sub 4//sup 2 -/ from forming a passive film rather than in attacking the film after it has formed. Alloyed Mo and aqueous MoO/sub 4//sup 2 -/ both inhibit pitting through incorporation into the passive film but incorporation from the solution is easily influenced by solution variables such as chloride concentration.

• Research Organization: Rensselaer Polytechnic Inst., Troy, NY (USA). Dept. of Materials Engineering
• DOE Contract Number: FG02-84ER45101
• OSTI ID: 5821267
• Report Number(s): DOE/ER/45101-1; ON: DE86011918
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360105* -- Metals & Alloys-- Corrosion & Erosion
ALLOYS
AQUEOUS SOLUTIONS
CHEMICAL REACTIONS
CHLORIDES
CHLORINE COMPOUNDS
CHROMIUM ALLOYS
CHROMIUM STEELS
CHROMIUM-MOLYBDENUM STEELS
CORROSION
CORROSION RESISTANCE
DISPERSIONS
HALIDES
HALOGEN COMPOUNDS
IRON ALLOYS
IRON BASE ALLOYS
MIXTURES
MOLYBDATES
MOLYBDENUM COMPOUNDS
OXYGEN COMPOUNDS
PASSIVATION
PITTING CORROSION
REFRACTORY METAL COMPOUNDS
SOLUTIONS
STEELS
TRANSITION ELEMENT COMPOUNDS