PREDICTION OF THE BEHAVIOUR IN PLASTIC FATIGUE OF STRUCTURAL STEELS ON THE BASIS OF THEIR TENSION CHARACTERISTICS

PREVISION DU COMPORTEMENT EN FATIGUE PLASTIQUE DES ACIERS DE CONSTRUCTION MECANIQUE A PARTIR DE LEURS CARACTERISTIQUES DE TRACTION

The authors have earlier presented a report on the influence of thermal treatment on the hardening or softening of steels subjected to cyclic plastic deformation. Their findings were: (1) the formation of an unstable phase (residual austenite) in the course of treatment produced by external hardening of steel subjected to cyclic plastic deformations; (2) the formation of stable phases in the course of treatment by wetting or tempering generally causes a softening corresponding to a reduction in the elastic limit; (3) the wetted state leads too often to a substantial cyclic hardening; (4) for those steels where the tensile curve is graduated in stages the phenomenon disappears. The paper showed that it is possible to predict correctly the thermal behaviour (hardening or softening) of steel alloys subjected to cyclic plastic deformation with the aid of tensile characteristics. With the aid of deformation tests applied up to failure point, it has been determined for the different alloys that in the field of oligocyclic fatigue the laws of behaviour link the amplitudes of plastic deformation and elasticity to the life span of the material. The authors show that plastic deformation is proportional to the extension and that elastic laws may be placed in the same order as the lengthening, while the "elastic" deformation is proportional to the mechanical strengths. To estimate the parameters of resistance to cyclic deformation, a method of prediction is proposed which makes it possible to trace with a high degree of accuracy the "elastic" and "plastic" laws, using only the parameters measured on the tensile curve. (TRRL)

• Authors:
  • Gallet, G
  • Lieurade, H P
• Publication Date: 1978-1

Language

• French

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 37-49
• Serial:
  • Revue de Metallurgie
  • Issue Number: 1

Subject/Index Terms

• TRT Terms: Alloy steel; Concrete hardening; Durability; Elastic limit; Elasticity (Mechanics); Failure; Fatigue (Mechanics); Fatigue tests; Hardness; Metal heating; Metallurgy; Plastic deformation; Rail steel; Softening point; Steel; Structural steel; Tension; Wetting
• Uncontrolled Terms: Heat treatment; Tensile stress
• Old TRIS Terms: Rail steel metallurgy; Steel metallurgy
• ITRD Terms: 5595: Deformation; 5910: Durability; 5520: Failure; 5579: Fatigue (mater); 6997: Frequency; 4722: Hardening; 3835: Hardening (heat treatment); 6743: Heat; 5922: Plasticity; 9063: Quality; 6251: Sample (mater); 4542: Steel; 5502: Tension; 6255: Test
• Subject Areas: Geotechnology; Highways; Materials; I34: Steels and Metals;

Filing Info

• Accession Number: 00312106
• Record Type: Publication
• Source Agency: Transport and Road Research Laboratory (TRRL)
• Files: ITRD, TRIS
• Created Date: Jul 22 1980 12:00AM