High-temperature tensile property measurements using digital image correlation over a non-uniform temperature field

Abstract

Standard test methods for measuring temperature-specific mechanical properties are typically specimen and time intensive when the influence of varying parameters is taken into consideration. Often, multiple specimens and test runs are required to build a complete database of constitutive parameters. This article presents a numerical–experimental methodology that employs digital image correlation to measure temperature-specific tensile properties of a 12% Cr steel. The methodology presents the unique ability to obtain temperature-specific properties from a single sample: the sample is subjected to a longitudinal thermal gradient through resistive heating in a thermomechanical loading system, while the full-field capabilities of digital image correlation and thermal imaging are used to measure strain and temperature surface maps, respectively. A study on the robustness of the methodology with regard to image saturation control and stress state found the setup capable of deformation measurement up to 900 °C. Elastic moduli and Poisson’s ratios were extracted in the 480 °C–600 °C range from a single specimen. The presented metrology sets the framework for investigations that are aimed at extracting temperature-specific mechanical properties for 12% Cr steels.