Accession Number : AD0428137


Title :   FRACTOGRAPHY. PART XIII EXAMINATION OF ELEVATEDTEMPERATURE FRACTURE IN A LOW-CARBON FREEMACHINING STEEL.


Descriptive Note : Interim rept.,


Corporate Author : NAVAL RESEARCH LAB WASHINGTON D C


Personal Author(s) : Dahlberg,E P ; Flint,J E


Report Date : Aug 1963


Pagination or Media Count : 15


Abstract : A small cylindrical steel collar adapted for use in a laboratory extrusion die assembly suddenly broke in a brittle manner into two pieces during an extrusion operation in which the temperature of the collar was at 600 F. It was suspected that this was above the transition temperature, and an investigation was made in order to extract such information as might be available and pertain to the problem of similar catastrophic rupturing of pressurized containers at elevated temperature. The electron microscope was employed to characterize the service fracture, which was concluded to have been generated by the growth and coalescence of voids around rod-shaped nonmetallic inclusions. This is an example of a brittle fracture occuring at a temperature too high for the cleavage mode to operate. (Author)


Descriptors :   *FRACTOGRAPHY , *FRACTURE(MECHANICS) , ELECTRON MICROSCOPY , STEEL , BRITTLENESS , TEMPERATURE , HIGH TEMPERATURE , SCIENTIFIC RESEARCH , MARTENSITE , IMPURITIES , MANGANESE COMPOUNDS , SULFIDES , MICROSTRUCTURE , HARDNESS , SURFACES


Distribution Statement : APPROVED FOR PUBLIC RELEASE