A new method for identification of the mechanism of corrosion fatigue crack growth

Book · Sun Dec 01 04:00:00 EST 1996

OSTI ID:397832

Shipilov, S A ^[1]

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

A new electrochemical method for identification of the mechanism of corrosion fatigue crack growth (FCG) has been proposed. The method is based on the discovered regularity of an ambiguous effect of short-term cathodic polarization on the corrosion FCG rates. The regularity is a common one for high strength steels, titanium alloys and magnesium alloy tested, and it implies that short-term cathodic polarization accelerates the corrosion FCG by several times, when maximum stress intensity K{sub max} and corresponding FCG rate exceed certain critical values, but when K{sub max} and corresponding FCG rate are lower than the critical values, the same cathodic polarization (with all other conditions being equal) retards or does not almost influence the corrosion FCG. It is concluded that the accelerated crack growth at cathodic potentials is due to hydrogen-induced cracking (HIC) appearance. Therefore, the critical values of K{sub max} and corresponding FCG rate are regarded as the ones corresponding to the beginning of corrosion FCG according to HIC mechanism.

• OSTI ID: 397832
• Report Number(s): CONF-960389--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AQUEOUS SOLUTIONS
CHEMICAL COMPOSITION
CORROSION FATIGUE
CRACK PROPAGATION
CRACKS
ELECTRIC POTENTIAL
ELECTROCHEMISTRY
EXPERIMENTAL DATA
FRACTURE MECHANICS
HYDROGEN
MAGNESIUM ALLOYS
SAMPLE PREPARATION
SCANNING ELECTRON MICROSCOPY
STEELS
STRESS INTENSITY FACTORS
STRESSES
TITANIUM ALLOYS