Tensile stress-strain analysis of cold worked metals and steels and dual-phase steels

A study has been made of the applicability of the differential Crussard-Jaoul (C-J) analysis that assumes the Ludwik power relation, the modified C-J analysis based on the Swift formula, and the Hollomon analysis to uniaxially prestrained metals and steels and high strength, formable, dual-phase steels. The pure aluminum and copper metals and a series of plain carbon steels with carbon ranging from 0.10 to 1.05 pct were uniaxially prestrained by a given amount of strain under ambient temperature. A plain carbon steel with carbon of 0.10 pct was utilized in manufacturing the dual-phase steels. An empirical analysis exhibited the limited applicability of the C-J analysis for the interpretation of the stress-strain relationship of uniaxially prestrained metals and steels. The C-J analysis was also less sensitive to changes in the deformation behavior of the dual-phase steels in which the ferrite matrix and the shape and distribution of the second phase martensite were altered by three heat treatments. The modified C-J analysis was most suitable for describing work-hardening of uniaxially prestrained metals and steels. This analysis revealed that the dual-phase steels deformed in two stages. The first stage was associated with deformation of the ferrite matrix, and the second stage was associated with uniform straining of ferrite and martensite. The more generally used Hollomon curves deviated from linearity over all the uniform strain range regardless of the uniaxially prestrained metals and steels and dual-phase steels. Thus, the Hollomon parameters could not be assigned to an entire curve.

[1]  W. Truszkowski.  Etude de l’hétérogénéité des métaux soumis à l’essai de traction , 1958 .

[2]  Ch. Crussard,et al.  Contribution à l'étude de la forme des courbes de traction des métaux et à son interprétation physique , 1950 .

[3]  R. Hertzberg,et al.  The role of mechanical properties in low-stress fatigue crack propagation , 1972 .

[4]  J. Hirth,et al.  Effects of microstructure on fracture toughness of a high-strength low-alloy steel , 1983 .

[5]  H. J. Kleemola,et al.  On the strain-hardening parameters of metals , 1974 .

[6]  R. Williams.  Deformation of nonrandom solid solutions and the calculation of magnetic anisotropy , 1973 .

[7]  H. W. Swift.  Plastic instability under plane stress , 1952 .

[8]  R. G. Davies.  Influence of martensite composition and content on the properties of dual phase steels , 1978 .

[9]  S. Monteiro,et al.  On the double-n behavior of iron , 1971 .

[10]  G. Smith,et al.  Crack initiation in an aligned titanium alloy containing an interface layer , 1981 .

[11]  S. Monteiro,et al.  An empirical analysis of titanium stress-strain curves , 1973 .

[12]  Paul Ludwik,et al.  Elemente der technologischen Mechanik , 1909 .

[13]  P. Forsyth,et al.  The Effect of Composition Changes on the Fracture Toughness of an Al-Zn-Mg-Cu-Mn Forging Alloy , 1973 .

[14]  K. Ono.  Strain-Hardening equations and uniform strain , 1972 .

[15]  S. Monteiro,et al.  The effects of temperature and purity on the second stage of hardening in polycrystalline α-titanium , 1972 .

[16]  Par B. Jaoul.  Etude de la forme des courbes de deformation plastique , 1957 .

[17]  W. R. Cribb,et al.  Concerning the analysis of tensile stress-strain data using log dσ/dεp versus log σ diagrams , 1973 .

[18]  D. C. Ludwigson,et al.  Modified stress-strain relation for FCC metals and alloys , 1971 .

[19]  J. Knott,et al.  Effects of dispersoid particles on toughness of high-strength aluminium alloys , 1981 .

[20]  R. G. Davies.  The deformation behavior of a vanadium-strengthened dual phase steel , 1978 .

[21]  Ch. Crussard,et al.  Rapport entre la forme exacte des courbes de traction des métaux et les modifications concomitantes de leur structure , 1953 .