Accession Number:

AD0725470

Title:

Fatigue Crack Growth Behavior of Four High Strength Steels in Two Humid Environments. Part I,

Descriptive Note:

Corporate Author:

NAVAL AIR DEVELOPMENT CENTER WARMINSTER PA AERO MATERIALS DEPT

Personal Author(s):

Report Date:

1971-01-29

Pagination or Media Count:

30.0

Abstract:

Fatigue crack growth rates dadN as a function of applied stress intensity amplitude delta K were determined for four high strength steels HP 9-4-.45, 18 Ni marage 250, D6Ac, AISI 4340 in air at 10 percent and at 80 percent relative humidities R.H.. All four steels demonstrated sensitivity to high humidity with crack growth rates in 80 percent R.H. air being one and one-half to two times as high as in 10 percent R.H. air. Overall crack growth rates of three steels, HP 9-4-.45, 18 Ni marage 250, and D6Ac, were similar, while rates for AISI 4340 were uniformly higher than those of the other three steels. Author

Subject Categories:

  • Aircraft
  • Metallurgy and Metallography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE