HYDROGEN EMBRITTLEMENT IN STEELS, TITANIUM ALLOYS, AND SEVERAL FACE- CENTERED CUBIC ALLOYS

Technical Report · Wed Apr 01 04:00:00 EST 1959

OSTI ID:4221308

Blanchard, P A; Quigg, R J; Schaller, F W; Steigerwald, E A; Troiano, A R

This report, which describes the influence of hydrogen on the mechanical properties of high strength steel, titanium and face-centered cubic metals, is divided into three sections. Delayed Failure In High Strength Steel. The initiation of localized cracking in a hydrogenated high strength steel specimen was found to be dependent on the development of a critical hydrogen concentration and relatively insensitive to the magnitude of the applied stress. The stress played an essential role in the delayed failure process by providing the means for grouping the hydrogen. Assuming that the rate of stressinduced diffusion was a direct function of the applied stress, the predicted relationship between incubation time and stress agreed reasonably well with experimental data. Hydrogen Embrittlement and Strain Aging In Titanium Alloys. Low Strain rate embrittlement in titanium alloys can be classified as a strain aging phenomenon. Prestraining and aging an alpha-beta titanium alloy resulted in a ductility minimum at some intermediate aging time. It appears that hydrogen migrates to a region of inhomogeneous strain, where a high stress state exists, and creates this embrittlement. The restoration of ductility at long aging times was attributed to recovery with subsequent redistribution of hydrogen. Low strain rate hydrogen embrittlement was obtained for an alpha alloy and a beta alloy. Hydrogen in small quantities seemed to aid creep resistance in the alpha alloy. The beta alloy was resistant to nominal quantities of hydrogen (420 ppm), but did show embrittlement at higher levels. Hydrogen Embrittlement of Several Face- Centered Cubic Alloys. The hydrogen embrittlement of austenitic Ni-Cr-Fe alloys and OFHC copper has been investigated. Ni-Cr-Fe alloys were embrittled by hydrogen and their embrittlement was demonstrated to be of the same nature as that of steel. A qualitative mechanism was presented which indicated that only the transition metals should be capable of conventional hydrogen embrittlement. This mechanism also accounted for the observed decrease of embrittlement in the austenitic Ni-Cr-Fe alloys with increasing (Fe + Cr) content. (auth)

• Research Organization: Case Inst. of Tech., Cleveland
• NSA Number: NSA-14-000624
• OSTI ID: 4221308
• Report Number(s): WADC-TR-59-172
• Country of Publication: United States
• Language: English

Related Subjects

AUSTENITE-- BRITTLENESS-- CHROMIUM ALLOYS-- CREEP-- DEFORMATION-- DIFFUSION-- DISTRIBUTION-- DUCTILITY-- FAILURES-- HEAT TREATMENTS-- HYDROGEN-- IRON ALLOYS-- MECHANICAL PROPERTIES-- NICKEL ALLOYS-- PHASE DIAGRAMS-- QUANTITY RATIO-- RECOVERY-- STABILITY-- STEELS-- STRESSES-- TITANIUM ALLOYS
COPPER-- TRANSITION METALS
METALS, CERAMICS, AND MATERIALS