Limitations of the Hollomon strain-hardening equation

Publisher Website
Google Scholar
Abstract
Conventional strength and strain-hardening parameters have been derived for idealized true-stress/true-strain curves obeying the Hollomon equation σ=Kpn, where K and n have values typical of real metals. All stress parameters are proportional to the constant K. The true tensile strength is almost independent of n, but the stress at 02% plastic strain is strongly dependent on n. The strain-hardening rate dσ/dp is significantly affected by n only when pp increases with increasing n when nn when n>02. The strain-hardening rate is not easily related to the parameters nσmax, nK or the 02% proof-stress/true-tensile-strength ratio. The magnitude of the strain hardening, given by Δσ = (σ2 - σ1), also has a maximum between n=01 and 03. With these results, assumptions and conclusions in the published literature are discussed and some are shown to be incorrect. It is concluded that for maximum strength and strain hardening in materials obeying the Hollomon equation, large values of K and n values between 01 and 03 are required.

This publication has 28 references indexed in Scilit: