High‐Temperature Nanoindentation of Metals: Assessing Thermal Drift, Frame Compliance, and Chemical Composition Effects on the Reported Mechanical Properties

High‐temperature nanoindentation measurements are compromised by instrument‐related artifacts, such as thermal drift and temperature‐dependent apparent frame compliance. In this study, we quantify the influence of these artifacts on apparent mechanical properties by comparing static nanoindentation across temperatures and by analyzing the resulting data with two processing routes: the classical Oliver–Pharr method and an automatic image recognition (AIR) method. Significant thermal drift was observed at elevated temperatures and was found to alter the apparent frame compliance and contact‐depth determination. Both analysis methods show a systematic reduction in hardness with increasing temperature. Multiple ferritic, martensitic, and austenitic steels as well as a Ni‐based alloy were examined to probe the compositional and microstructural contributions to thermal stability. Despite substantial scatter inherent to elevated‐temperature testing, statistical analysis indicates that Cr and Ni additions improve resistance to softening. Combining Oliver–Pharr and AIR analyses enables more reliable extraction of mechanical properties related to the alloy composition at elevated temperatures when instrument artifacts are explicitly considered.