Effect of externally added molybdate on repassivation and stress corrosion cracking of type 304 stainless steel in hydrochloric acid

Journal Article · Mon Apr 01 04:00:00 EST 1996 · Corrosion

DOI:https://doi.org/10.5006/1.3293636· OSTI ID:218583

Devasenapathi, A; Raja, V S ^[1]

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1. Indian Inst. of Tech., Bombay (India). Corrosion Science and Engineering Program

The effect of externally added molybdate (MoO{sub 4}{sup 2{minus}}) on the repassivation and SCC behavior of type 304 (UNS S30400) stainless steel (SS) was investigated in 1 M hydrochloric acid (HCl) at open-circuit potential (OCP). With the addition of MoO{sub 4}{sup 2{minus}}, the time to failure initially decreased but then gradually increased. From studies using potential-vs-time data, the scratching electrode technique, and electron spectroscopy for chemical analysis (ESCA), the initial decrease in the time to failure at lower MoO{sub 4}{sup 2{minus}} concentrations was attributed to an increase in the cathodic reaction rate and a consequent increase in anodic dissolution. The increase in the time to failure at higher MoO{sub 4}{sup 2{minus}} concentrations was attributed to the reduction in anodic dissolution with a strong tendency for MoO{sub 4}{sup 2{minus}} deposition on the bare metal surface.

• Sponsoring Organization: USDOE
• OSTI ID: 218583
• Journal Information: Corrosion, Journal Name: Corrosion Journal Issue: 4 Vol. 52; ISSN 0010-9312; ISSN CORRAK
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ADSORPTION
CATALYTIC EFFECTS
CORROSION PROTECTION
CORROSION RESISTANCE
CORROSIVE EFFECTS
CRACK PROPAGATION
DIAGNOSTIC TECHNIQUES
HYDROCHLORIC ACID
METALLURGICAL EFFECTS
MOLYBDATES
MOLYBDENUM
PASSIVATION
STAINLESS STEEL-304
STRESS CORROSION