ISSN: 1945-7553
CODEN: JTEVAB
Page Count: 9

Comparison of Stress Corrosion Cracking Properties of Several Aircraft Structural Alloys

Ryder, JT
Research scientist, group engineer, and research scientistmembers of ASTM, Rye Canyon Research Laboratory, Lockheed-California Co., Burbank, Calif.

Krupp, WE
Research scientist, group engineer, and research scientistmembers of ASTM, Rye Canyon Research Laboratory, Lockheed-California Co., Burbank, Calif.

Pettit, DE
Research scientist, group engineer, and research scientistmembers of ASTM, Rye Canyon Research Laboratory, Lockheed-California Co., Burbank, Calif.

Hoeppner, DW
Professor of engineeringMember of ASTM, University of Missouri, Columbia, Mo.

Abstract

Sustained load subcritical flaw growth characteristics of five alloys of interest to aircraft designers were investigated. The aluminum alloy (2024-T851) and steel alloy (18Ni-maraging) were studied in 3.5% sodium chloride solution and high humidity air environments while two of the titanium alloys, Ti-6Al-4V (recrystallized annealed) and Ti-6A1-6V-2Sn (solution-treated and overaged), were also investigated in these environments plus sump tank water. The Ti-6Al-4V (beta) alloy was tested in 3.5% sodium chloride solution. Wide differences between the alloys were noted not only in their cracking rates but also in their responses to similar loads and environments. Specimen thickness was found to have an important effect on stress corrosion susceptibility of the titanium alloys. Many coupons of specific titanium alloys had significant subsurface crack growth without visible surface growth. For these alloys, no precise threshold for stress corrosion cracking could be defined.

Keywords:
stress corrosion, aluminum, steels, titanium, high humidity, sump tank water, salt water

Paper ID: JTE10930J
DOI: 10.1520/JTE10930J
ASTM International is a member of CrossRef.