SEDL / STP / STP1072-EB / STP24142S

The Effect of Fatigue Pre-Cracking Versus V-Notching on Impact Testing of Charpy Specimens

Fields, BA
guest scientist in the Metallurgy Divisionmechanical engineer in the Metallurgy Divisionmetallurgist and a scientific advisor to the director of the Institute for Materials Science and Engineering, National Institute of Standards and Technology (NIST)NISTNIST, Gaithersburg, MD

Low, SR
guest scientist in the Metallurgy Divisionmechanical engineer in the Metallurgy Divisionmetallurgist and a scientific advisor to the director of the Institute for Materials Science and Engineering, National Institute of Standards and Technology (NIST)NISTNIST, Gaithersburg, MD

Early, JG
guest scientist in the Metallurgy Divisionmechanical engineer in the Metallurgy Divisionmetallurgist and a scientific advisor to the director of the Institute for Materials Science and Engineering, National Institute of Standards and Technology (NIST)NISTNIST, Gaithersburg, MD

Pages: 14    Published: Jan 1990

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Abstract

Charpy impact testing was carried out on both V-notch and fatigue pre-cracked specimens of two steels: AAR M128, and ASTM A212-65. Values of total energy absorbed, lateral expansion and shear fracture appearance were found for both types of specimen. The total energies absorbed by the fatigue pre-cracked specimens were markedly less than those by V-notch samples.

Transition temperature ranges were found for both the V-notch and pre-cracked specimens. The energy absorption results show a small increase in transition temperatures for the pre-cracked specimens. The lateral expansion results are the same in both types of specimen for the AAR M128 steel and show only a small change in the ASTM A212-65 steel. Also for the A212 steel the shear fracture appearance results can be represented by a single curve for V-notch and pre-cracked specimens. However, for the M128 steel these curves occur at lower temperatures for the pre-cracked specimens.