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) : Miller,Martin S


Report Date : 09 Jan 1964


Pagination or Media Count : 8


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)


Descriptors :   *STAINLESS STEEL , CRYOGENICS , STRETCH FORMING , NIOBIUM ALLOYS , ALUMINUM ALLOYS , TENSILE PROPERTIES , DEFORMATION , STRESSES , MECHANICAL PROPERTIES , CHEMICAL ANALYSIS , AUSTENITE


Distribution Statement : APPROVED FOR PUBLIC RELEASE