Microscopic Observations of Adiabatic Shear Bands in Three Different Steels

Abstract

Microscopic observations are made of the shear band material in three different steels: (1) an AISI 1018 cold rolled steel, (2) a high strength low alloy structural steel, and (3) an AISI 4340 VAR steel tempered to either of two hardnesses, RHC 44 or 55. Dynamic deformation in shear was imposed to produce shear bands in all the steels tested. It was found that whenever the shear band led to fracture of the specimen, the fracture occurred by a process of void nucleation and coalescence; no cleavage was observed on any fracture surface, including the most brittle of the steels tested (RHC = 55). This is presumably due to the softening of the shear band material that results from the local temperature rise occurring during dynamic deformation. Differences in shear band behavior between the various microstructures are also described. Keywords: Adiabatic shear bands; Steel; Fractography; Voids; Microcracks.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1988
Accession Number
ADA202522

Entities

People

  • J. Duffy
  • K. Cho
  • Y. C. Chi

Organizations

  • Brown University

Tags

Communities of Interest

  • Air Platforms
  • Weapons Technologies

DTIC Thesaurus Topics

  • Deformation (Mechanics)
  • Engineering
  • Grain Boundaries
  • Hardness
  • Heat Treatment
  • Materials
  • Mechanical Properties
  • Mechanics
  • Phase Transformations
  • Photographs
  • Shear Bands
  • Shear Stresses
  • Strain Rate
  • Stress Strain Relations
  • Stresses
  • Structural Components
  • Structural Steel

Fields of Study

  • Engineering
  • Materials science

Readers

  • Materials Science (Mechanical Engineering).