Accession Number:

AD0431651

Title:

DEVELOPMENT OF HIGH-STRENGTH ALLOYS BY CRYOGENIC STRETCH-FORMING.

Descriptive Note:

Quarterly technical rept. no. 3, 10 Oct 639 Jan 64,

Corporate Author:

ARDE-PORTLAND INC PARAMUS N J

Personal Author(s):

Report Date:

1964-01-09

Pagination or Media Count:

8.0

Abstract:

Twelve heats were procured and tested under the program. Four additional cobalt-molybdenummodified heats are under test, and another six sets are being machined to tensile coupons. High-age-response Heat RV 1252 presented no problems in welding. However, notch tests NASA notch on this material revealed a high notch sensitivity at room temperature. The poor notch response caused rejection of this composition for use in vessel fabrication. A second columbium-aluminum heat, RV 1336, showed improved notch strength due mainly to a lower carbon content. Room-temperature notch strength ratios below one precluded this material from immediate acceptance. Additional heats tested strengthen the conclusion, advanced in a previous report, that unmodified vacuum-melted 301 stainless steel has negligible strength increase after an aging treatment. Specific alloys must be added to develop an aging system in the steel. The columbium-aluminum system does this effectively, but it renders the material notch-sensitive. Several air-melted heats tested confirmed the reliability of the computer analysis in predicting tensile strength. Deviations between predicted and measured roomtemperature tensile strengths ranged from 2 to 10 ksi. Author

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Distribution Statement:

APPROVED FOR PUBLIC RELEASE