Adiabatic Heating of Austenitic Stainless Steels at Different Strain Rates

Abstract

This work focuses on the effect of strain rate on the mechanical response and adiabatic heating of two austenitic stainless steels. Tensile tests were carried out over a wide range of strain rates from quasi-static to dynamic conditions, using a hydraulic load frame and a device that allowed testing at intermediate strain rates. The full-field strains of the deforming specimens were obtained with digital image correlation, while the full field temperatures were measured with infrared thermography. The image acquisition for the strain and temperature images was synchronized to calculate the Taylor-Quinney coefficient (β). The Taylor-Quinney coefficient of both materials is below 0.9 for all the investigated strain rates. The metastable AISI 301 steel undergoes an exothermic phase transformation from austenite to α'-martensite during the deformation, which results in a higher value of β at any given strain, compared to the value obtained for the more stable AISI 316 steel at the same strain rate. For the metastable 301 steel, the value of β with respect to strain depends strongly on the strain rate. At strain rate of 85 s −1 , the β factor increases from 0.69 to 0.82 throughout uniform elongation. At strain rate of 10 −1 s −1 , however, β increases during uniform deformation from 0.71 to a maximum of 0.95 and then decreases to 0.91 at the start of necking.Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Strain Rate Dependent Ductility and Strain Hardening in Q&P Steels

“…For example, the Taylor-Quinney coefficient of a fully stable austenitic steel (AISI 316) was lower than a metastable austenitic steel (AISI 301), the latter of which presumably exhibited more DIMT during uniaxial tension testing and thus more deformation-induced heating. [81] Based on these findings, the study proved the necessity of simultaneous measurement of surface temperature and strain for validating deformation-induced heating models of steels containing metastable austenite. This experimental approach, coupled with in-situ measurement of austenite volume fraction, would be highly useful for resolving DIMT and forming response under nonlinear strain paths, strain states including but not limited to uniaxial tension, and strain rates relevant to stamping (10 À1 to 10 s À1 ) and vehicle crashes (10 2 to 10 3 s À1 ).…”

“…austenitic stainless steels. [81] Va´zquez-Ferna´ndez et al reported that the extent of heat generation associated with the martensitic transformation can be incorporated into the model by changes in the Taylor-Quinney coefficient. For example, the Taylor-Quinney coefficient of a fully stable austenitic steel (AISI 316) was lower than a metastable austenitic steel (AISI 301), the latter of which presumably exhibited more DIMT during uniaxial tension testing and thus more deformation-induced heating.…”

“…As discussed previously, specimen heating is also influenced by the extent of the exothermic martensite transformation. [81] Therefore, deformation processing factors that influence DIMT (such as strain rate and strain state), could influence the Taylor-Quinney coefficient and the flow behavior, thereby controlling the temperature rise under adiabatic conditions. In cold stamping operations, several factors could further influence heat flow and consequently control DIMT.…”

Impact Behavior of Additively Manufactured Stainless Steel Auxetic Structures at Elevated and Reduced Temperatures

“…Commonly, only wrought metallic materials have been investigated. In the case of the austenitic stainless steel, strain rate sensitivity and coupled thermomechanical behavior of the bulk specimens have been investigated in research studies covering topics like microstructure characterization, [ 5 ] adiabatic heating, [ 6 ] or constitutive modelling. [ 7–9 ] Kluczyński et al dealt with the influence of additive manufacturing production parameters on the resulting mechanical parameters.…”

Formulation of a Generalized Flow Curve for 0.2% Carbon Steel under High-speed Hot Forming Conditions by a Regression Method

“…As can be seen from Eq. ( 7), a high strain rate can lead to greater internal heat generation, and it has been experimentally demonstrated using an IR camera by Vazquez-Fernandez et al and Seidt et al 14,15) The calculated temperature distribution after a 75% reduction in height at each strain rate and its initial state before deformation visualized by microAVS ® is presented in Fig. 5.…”