University of Illinois Urbana-Champaign

Cyclic Deformation and Fatigue Behavior of Hardened Steels

Landgraf, R.W.

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https://hdl.handle.net/2142/441

Description

Title
Cyclic Deformation and Fatigue Behavior of Hardened Steels
Author(s)
Landgraf, R.W.
Issue Date
1968-11
Keyword(s)
  • Mechanics
  • Metals
  • Steel
Abstract
Changes in deformation resistance are studied during completely reversed strain cycling of steels hardened to yield strengths in excess of 200 ksi by quenching and tempering, quenching and deforming at elevated temperature, ausforming and maraging. Untempered steel and ausformed steel exhibit cyclic hardening; slightly tempered steel is cyclically stable. Varying amounts of cyclic softening occur in intermediate hardness quenched and tempered steel, quenched and deformed steel and maraging steel. Such cyclically induced changes can be predicted from a steel's monotonic strain hardening exponent and are characterized in terms of a cyclic stress -strain curve. Log-log linear relations between elastic strain and fatigue life and plastic strain and fatigue life adequately describe the fatigue behavior of hardened steels. Monotonic true fracture strength and ductility approximate intercept values in the relations thus providing reliable indications of a steel's fatigue resistance. The optimum condition for maximum fatigue resistance shifts from high hardnesses at long lives, where strength is the determining factor, to lower hardnesses at shorter lives, where ductility becomes more important. Trends between structure and cyclic behavior are discussed along with approaches for attaining improved fatigue resistance in steel.
Publisher
Department of Theoretical and Applied Mechanics (UIUC)
Series/Report Name or Number
TAM Reports 320, (1968)
ISSN
0073-5264
Type of Resource
text
Language
en
Permalink
http://hdl.handle.net/2142/441
Sponsor(s)/Grant Number(s)
Caterpillar Tractor Co 68/11; La Salle Steel Co 68/11; United States Steel Corp 68/11

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Technical Reports - Theoretical and Applied Mechanics (TAM)
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