Flow Stress of Metals and Its Application in Metal Forming Analyses

Abstract

Forming load and energy can be determined if the flow stress of the deforming, material is known at the temperature and strain-rate conditions existing during the process. In this study domestic and foreign melalforming articles were reviewed and the available flow stress data have been presented for selected carbon, stainless, and tool steels; aluminum, copper, and titanium alloys; magnesium, uranium, zircaloy, molybdenum, tungsten, tantalum, and niobium. Whenever possible, data are presented by calculating and tabulating coefficients K and n to express strain hardening (flow stress σ¯ = Kε¯n), and C and m to express strain-rate dependency (σ¯=Cε¯˙m). Examples are given to illustrate the use of flow-stress data with simple formulas in predicting pressures in upset forging, closed-die forging, and cold extrusion.

Mathematical modelling of the stress–strain curves of Ti-IF steel at high temperature

“…In order to employ the more advanced modelling techniques such as finite element analysis, the constitutive behaviour at each point during the deformation regime must be determined. Several equations have been successfully developed to relate stress to strain although they often contain constants that have no metallurgical significance [1,2].…”

Modeling of dynamic expansion of thick‐walled cylinder under high strain rate loading with strain rate sensitivity analysis

“…In this case, for dynamic behavior of the material, we choose on empirical grounds which the dynamic strength can be written in terms of the static yield stress and strain rate sensitivity or strain rate hardening exponent as Eq. (19) with σ 0 ¼ 260 MPa and various values of m between 0.02 to 0.20 [22]. The cylinder filled with explosive material TNT and detonated axially to expand in the radial direction and subject to an internal pressure follows Jones-Wilkins-Lee equation of state in the dynamic analysis.…”

A technical note on the role of process parameters in predicting flow behavior of plasticine using design of experiment

“…method for providing information on the plastic flow of metals, load predictions, and two and three dimensional strain distributions in MFP [1][2][3][4]. Successful implementation of the PMT is based on the simulation of an actual MFP utilizing a model material and tools under conditions similar to the actual process.…”