Notched specimens of titanium alloy and Inconel-718 exhibit little reduction of notch strength at certain low temperatures under 2000 lb/sq in. hydrogen, unnotched specimens are not embrittled at these temperatures. The degree of Inconel-718 embrittlement is lower than earlier observations under 1000 lb/sq in. hydrogen

Chandler, W. T.

Walter, R. J.

English

NASA Technical Reports Server

November 1970	 Brief 70-10364 
NASA TECH BRIEF	
0<SM,A] 
NASA Tech Briefs announce new technology derived from the U.S. space program. They are issued to encourage commercial 
application. Tech Briefs are available on a subscription basis from the Clearinghouse for Federal Scientific and Technical 
Information, Springfield, Virginia 22151. Requests for individual copies or questions relating to the Tech Brief program may 
be directed to the Technology Utilization Division, NASA, Code UT, Washington, D.C. 20546. 
Low-Temperature Embrittlement of Ti-6A1-4V and Inconel-7 18 
by High-Pressure Hydrogen 
Tensile properties are reported of notched or 
unnotched specimens of titanium alloy Ti-6Al-4V 
(STA) at 70°, —109°, and —320°F under air at 1 atm 
or hydrogen or helium at 1000 and 2000 lb/in. 
Under 200-lb/in hydrogen the notch strength was 
reduced by about 45% at 70°F, 8% at - 109°F, and 
nil at —320°F; unnotched specimens essentially were 
not embrittled at these temperatures. 
Information is also available on tensile properties of 
notched or unnotched specimens of lnconel-718 at 
temperatures of 140°, 70°, —109°, and —320°F under 
air at 1 atm or hydrogen or helium at 1000 and 2000 
lb/in 2 . Under hydrogen at 2000 lb/in' the notch 
strength was reduced by about 15% at 70° and 140°F 
and almost nil at —109° and —320°F; unnotched speci-
mens were not embrittled. This degree of embrittle-
ment is much lower than earlier observations under 
1000-lb/in 2 hydrogen.
The 1000-cycle fatigue strength of precracked speci-
mens of Inconel-718 was 22% less under hydrogen at 
2000 lb/in' than under the same concentration of 
helium. 
Note: 
Requests for further information may be directed to: 
Technology Utilization Officer 
Code A&TS-TU 
Marshall Space Flight Center 
Huntsville, Alabama 35812 
Reference: TSP70-10364 
Patent status: 
No patent action is contemplated by NASA. 
Source: R. J. Walter and W. T. Chandler of 
North American Rockwell Corporation 
under contract to 
Marshall Space Flight Center 
(MFS-18753) 
Category 04 
This document was prepared under the sponsorship of the National 
Aeronautics and Space Administration. Neither the United States 
Government nor any person acting on behalf of the United States
Government assumes any liability resulting from the use of the 
information contained in this document, or warrants that such use 
will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19700000351 2020-03-17T00:40:36+00:00Z


Low-temperature embrittlement of Ti-6Al-4V and Inconel-718 by high pressure hydrogen

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