Corrosion fatigue crack growth behavior of titanium alloys in aqueous solutions

Journal Article · Thu Jan 01 04:00:00 EST 1998 · Corrosion

DOI:https://doi.org/10.5006/1.3284825· OSTI ID:644333

Shipilov, S A ^[1]

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1. Russian Academy of Sciences, Moscow (Russian Federation). Inst. of Physical Chemistry

The corrosion fatigue crack growth (FCG) behavior, the effect of applied potential on corrosion FCG rates, and the fracture surfaces of VT20 (near-{alpha}) and TS6 (near-{beta}) titanium alloys were studied. Environments were aqueous solutions of sodium chloride (NaCl), sodium hydroxide (NaOH), potassium hydroxide (KOH), ferric chloride (FeCl{sub 3}), and chromic acid (H{sub 2}CrO{sub 4}) with and without NaCl. Depending upon solution composition, corrosion FCG rates were found to be higher or lower than those in air. Cathodic polarization retarded the corrosion FCG, while anodic polarization accelerated insignificantly or almost did not influence it in most of the solutions investigated. However, cathodic polarization accelerated corrosion FCG in 0.6 M FeCl{sub 3} and 0.5 M to 2 M H{sub 2}CrO{sub 4} + 0.01 M to 0.1 M NaCl solutions by a dozen times when the maximum stress intensity (K{sub max}) exceeded certain critical values. When K{sub max} was lower than the critical values, the same cathodic polarization (with all other /conditions being equal) retarded corrosion FCG. Results suggested the accelerated crack growth at cathodic potentials resulted from hydrogen-induced cracking (HIC). Therefore, critical values of K{sub max}, as well as the stress intensity range ({Delta}K) were regarded as corresponding to the beginning of corrosion FCG according to a HIC mechanism and designated as K{sub HIC} and {Delta}K{sub HIC}.

• Sponsoring Organization: USDOE
• OSTI ID: 644333
• Journal Information: Corrosion, Journal Name: Corrosion Journal Issue: 1 Vol. 54; ISSN 0010-9312; ISSN CORRAK
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AQUEOUS SOLUTIONS
CATHODIC PROTECTION
CHLORIDES
CHROMIC ACID
CORROSION FATIGUE
CRACK PROPAGATION
HYDROGEN EMBRITTLEMENT
HYDROXIDES
TITANIUM BASE ALLOYS