Accession Number : AD0467523

Title :   THE EFFECT OF INELASTIC TENSILE PRESTRAIN ON THE BRITTLE FRACTURE PROPERTIES OF ANNEALED 4140 STEEL.

Descriptive Note : Technical rept.,

Corporate Author : MECHANICAL TECHNOLOGY INC LATHAM NY

Personal Author(s) : McLaughlin, D. W.

Report Date : 06 MAY 1965

Pagination or Media Count : 49

Abstract : An experimental study is reported that determines the effect of increasing amounts of inelastic tensile prestrain on the brittle fracture behavior of annealed AISI 4140 steel. Fracture characteristics of both prestrained and unstrained material were measured with V-notch Charpy specimens and drop-weight specimens. Specimens were prestrained to 1.3, 2.7, and 7.8 percent inelastic strains. Significant changes were observed in the slope, upper energy shelf and temperature location of the Charpy energy-temperature curve. The nil-ductility transition temperature (NDT), NDT energy 'fix,' and the Charpy fracture appearance curve also were affected markedly by inelastic prestrain. An introductory review of brittle fracture is presented. Emphasis is given to the transition temperature method of fracture analysis and to the design approach embodied in the Fracture Analysis Diagram developed at the U. S. Naval Research Laboratory. The design significance of the experimental data in interpreted in terms of their effect on the Fracture Analysis Diagram. (Author)

Descriptors :   (*STEEL, BRITTLENESS), (*BRITTLENESS, FRACTURE(MECHANICS)), TENSILE PROPERTIES, STRAIN(MECHANICS), HEAT TREATMENT, TRANSITION TEMPERATURE, DUCTILITY, TEMPERATURE, TABLES(DATA), EXPERIMENTAL DATA.

Distribution Statement : APPROVED FOR PUBLIC RELEASE