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Title: The strain-rate sensitivity of high-strength high-toughness steels.

Abstract

The present study examines the strain-rate sensitivity of four high strength, high-toughness alloys at strain rates ranging from 0.0002 s-1 to 200 s-1: Aermet 100, a modified 4340, modified HP9-4-20, and a recently developed Eglin AFB steel alloy, ES-1c. A refined dynamic servohydraulic method was used to perform tensile tests over this entire range. Each of these alloys exhibit only modest strain-rate sensitivity. Specifically, the strain-rate sensitivity exponent m, is found to be in the range of 0.004-0.007 depending on the alloy. This corresponds to a {approx}10% increase in the yield strength over the 7-orders of magnitude change in strain-rate. Interestingly, while three of the alloys showed a concominant {approx}3-10% drop in their ductility with increasing strain-rate, the ES1-c alloy actually exhibited a 25% increase in ductility with increasing strain-rate. Fractography suggests the possibility that at higher strain-rates ES-1c evolves towards a more ductile dimple fracture mode associated with microvoid coalescence.

Authors:
 [1]; ;
  1. (AFRL/MNMW, Eglin AFB, FL)
Publication Date:
Research Org.:
Sandia National Laboratories
Sponsoring Org.:
USDOE
OSTI Identifier:
902598
Report Number(s):
SAND2007-0036
TRN: US200718%%86
DOE Contract Number:
AC04-94AL85000
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ALLOYS; COALESCENCE; DUCTILITY; FRACTOGRAPHY; FRACTURES; SENSITIVITY; STEELS; STRAIN RATE; YIELD STRENGTH; Tensile properties.; Steel alloys.; Steel-Metallurgy.

Citation Formats

Dilmore, M.F., Crenshaw, Thomas B., and Boyce, Brad Lee. The strain-rate sensitivity of high-strength high-toughness steels.. United States: N. p., 2006. Web. doi:10.2172/902598.
Dilmore, M.F., Crenshaw, Thomas B., & Boyce, Brad Lee. The strain-rate sensitivity of high-strength high-toughness steels.. United States. doi:10.2172/902598.
Dilmore, M.F., Crenshaw, Thomas B., and Boyce, Brad Lee. Sun . "The strain-rate sensitivity of high-strength high-toughness steels.". United States. doi:10.2172/902598. https://www.osti.gov/servlets/purl/902598.
@article{osti_902598,
title = {The strain-rate sensitivity of high-strength high-toughness steels.},
author = {Dilmore, M.F. and Crenshaw, Thomas B. and Boyce, Brad Lee},
abstractNote = {The present study examines the strain-rate sensitivity of four high strength, high-toughness alloys at strain rates ranging from 0.0002 s-1 to 200 s-1: Aermet 100, a modified 4340, modified HP9-4-20, and a recently developed Eglin AFB steel alloy, ES-1c. A refined dynamic servohydraulic method was used to perform tensile tests over this entire range. Each of these alloys exhibit only modest strain-rate sensitivity. Specifically, the strain-rate sensitivity exponent m, is found to be in the range of 0.004-0.007 depending on the alloy. This corresponds to a {approx}10% increase in the yield strength over the 7-orders of magnitude change in strain-rate. Interestingly, while three of the alloys showed a concominant {approx}3-10% drop in their ductility with increasing strain-rate, the ES1-c alloy actually exhibited a 25% increase in ductility with increasing strain-rate. Fractography suggests the possibility that at higher strain-rates ES-1c evolves towards a more ductile dimple fracture mode associated with microvoid coalescence.},
doi = {10.2172/902598},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2006},
month = {Sun Jan 01 00:00:00 EST 2006}
}

Technical Report:

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