Effect of Strain Rate on the Yield Stress of Ferritic Stainless Steels

Abstract

The effect of strain rate on the yield stress of ferritic stainless steel sheet was experimentally determined and a previously developed model was applied to the data. Five ferritic stainless steel alloys, including one in two thicknesses, were mechanically tested at room temperature in uniaxial tension at strain rates ranging from 0.001 to 300 s -1 , and low-strain-rate tests were selectively performed at nonambient temperatures. The hypothesis that ferritic stainless steels react similarly to strain rate as mild steels was investigated by the application of a widely accepted strengthening model, based on body-centered-cubic (bcc) crystal lattice deformation mechanisms, to the experimental data. [1] Yield stresses were compared to model predictions and good agreement was found. The results allow for the prediction of yield stresses for these materials over strain rate ranges of 0.001 to 300 s -1 , and as a function of test temperature. Model parameters for the ferritic stainless steels were reasonable relative to those previously reported for pure bcc ferritic iron. [1] A correlation between the effect of alloying additions on solid solution strengthening and the athermal component of shear stress is also suggested. The results allow prediction of yield stress of ferritic stainless steels over a wide range of strain rates and temperatures.

Effect of strain rate on the forming behaviour of sheet metals

“…As is the case for most TRIP steels, the CMnAl TRIP steel exhibits an increase of both the yield stress and the elongation as the strain rate increases (Van Slycken et al, 2006). For AISI 409, or more generally for ferritic stainless steels, irrespective of the absolute value of the yield stress, the increase of yield stress as a function of the strain rate, is very similar to that of pure ferritic iron and low-carbon steels (Clarke et al, 2008). For DC04 a remarkable increase of strength is observed as the strain rate increases, however with a decreasing ductility (Schael and Bleck, 2001).…”

Plastic deformation of structural steels under hot-working conditions

“…This is also the case for a number of different approaches which combine the STG model with artificial neural networks modeling and polynomial fitting for determining the strain dependence of the different parameters involved in the constitutive relation [31][32][33][34][35][36]. In the past few years, a number of constitutive relationships developed for analyzing the deformation behavior of steels at elevated temperatures [37][38][39] have also been formulated on the basis of a modified form of the model advanced by Zerelli and Armstrong [40], as well as on different physically-based constitutive approaches [2,[41][42][43][44].…”

A Modified Eyring Equation for Modeling Yield and Flow Stresses of Metals at Strain Rates Ranging from 10−5to 5 × 104 s−1

“…Figure 5 shows the capability of the new equation to catch the behavior for strain rates up to 5 × 10 4 s −1 . [37] and Blazynski [38]) and new modified Eyring equation for annealed mild steel. The last example is dealing with tensile yield and ultimate stress of Ti-47Al-2Mn-2Nb ( Figure 6).…”