Constitutive Relationships for Hot Deformation of A Carbon Steel: A Comparison Study of Compression Tests and Torsion Tests

Abstract

A 0.34% carbon steel was subjected to hot working (800-1100°C) by Gleeble compression to 0.7 strain at strain rates of 0.1-8 S-I, cam plastometer compression to 0.4 strain at strain rates of 3.5-100 s-1 and torsion to fracture strains~8 at strain rates of 0.05-4 s-1. The compressive flow curves exhibited continual hardening towards saturation except at high temperatures or low strain rates where work softening finally occurred; in torsion, the curves exhibited the peak, softening and steady state characteristics of dynamic recrystallization. The sinh-Arrhenius constitutive equation was found suitable for describing the compression tests at a series of strain levels. The constants are power functions of strain with negative exponents; however, they differ for the two compression techniques as a result of anvil/ specimen contact friction in the Gleeble tests and the presence of a glass lubricant in the cam plastometer. Each set of constants can be employed to predict the flow curves of the other compression test with errors of only 7% as well as the stresses at the peak strains in torsion.Resume-Un acier 0.34% carbone a ete soumis a une deformation de 0.7 a chaud (800-1 100°C) lors d'une compression de Gleeble (e = 0.

Hot Deformation of 304 Type Austenitic Stainless Steel at High Strain Rates.

“…The advantages and disadvantages of each experimental technique when compared to one another in respect to their performances as a tool for hot rolling simulation are well known and well documented. [6][7][8][9][10][11] Torsion, particularly, is often employed not only to simulate hot rolling but also to produce stress-strain curves for the derivation of constitutive equations suitable to be used in flow curve modeling. 12) Mechanical testing, however, presents some limitations, the most serious of them, perhaps, regards the maximum strain rate attainable during deformation.…”

Hot Deformation of Austenitic Stainless Steel Type 316 up to Strain Rates of 100 s-1

“…From those, the temperature seems to be the most important since both softening and hardening mechanisms are thermally activated. Among the experimental techniques, tests such as axial [7][8][9] and plane strain compression 10) as well as torsion [11][12][13] have been frequently reported in the literature. The advantages and disadvantages of each experimental technique when compared to one another in respect to their performances as a tool for hot rolling simulation are well known and well documented.…”

Regression Method of Determining Generalized Description of Flow Curve of Steel under Dynamic Recrystallization

“…Such a flow curve was obtained in previous research studies. [4][5][6][7][8][9][10][11][12][13] However, a more precise description of a generalized flow curve is desired. Also, the number of generalized flow curves available at present should be increased to cover more types of steel with various alloy compositions that have been forged or rolled.…”