Accession Number : AD0664888

Title :   DYNAMIC SHEAR STRESS - STRAIN - STRAIN RATE RELATIONS OF IRON,

Corporate Author : AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS

Personal Author(s) : Yen,Charles C. S. ; Yew,Ching H.

Report Date : NOV 1967

Pagination or Media Count : 27

Abstract : The mechanical behavior of Armco iron and Ferrovac E iron under torsional impact loading was studied, and an experimental technique similar to the split Hopkinson pressure bar method was used. The shear stress--strain curves were determined at shear strain rates from 1,000,000 to 800 per sec. The tested specimens were examined metallographically. The flow stress of both irons was sensitive to the strain rate and exhibited similar trends. The upper yield point of Armco iron was more sensitive to the strain rate than the Ferrovac E iron when the shear strain rate was higher than 2 per sec. When the shear strain rate was >250 per sec, the Armco iron became brittle and failed catastrophically without appreciable plastic flow. In the brittle fracture, the main cracks ran along about 45 deg to the specimen length, indicating a tension failure instead of shear, and followed the grain boundaries. (Author)

Descriptors :   (*IRON, MECHANICAL PROPERTIES), SHEAR STRESSES, IMPACT TESTS, STRAIN(MECHANICS), DUCTILITY, METALLOGRAPHY, FRACTURE(MECHANICS), BRITTLENESS, TWINNING(CRYSTALLOGRAPHY), SENSITIVITY, TENSILE PROPERTIES, MICROSTRUCTURE, CRACKS, PLASTIC PROPERTIES, DEFORMATION, TEST METHODS

Subject Categories : Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE