Plane Strain Fracture Toughness of Some Cryogenic Materials at Room and Subzero Temperatures
SourceAn investigation was conducted to measure the plane strain fracture toughness, KIc, of eight potential cryogenic service alloys at 75, -100, and -321 F. The test materials included 7039-T61 and 2021-T81 aluminum alloys, Ti-6Al-4V STA in both alpha+beta and beta processed conditions, and the following steels: ASTM A553-A, PH 13-8Mo (H 1150-M), HP 9-4-20, and 18Ni (200 grade) maraging.
Results include both fracture toughness and tensile data as a function of test temperature for each alloy, together with overall comparisons in terms of the plane strain crack size factor, (KIc/σys)2, versus yield strength and yield strength to density ratio.
In cases where valid KIc data could not be generated, the appropriate aspects of the ASTM Tentative Method of Test for Plane Strain Fracture Toughness of Metallic Materials (E 399 - 70T) are discussed.