Abstract

Physical-based hydrogen storage technologies are among the most promising pathways toward achieving global energy transition goals by 2050, particularly for transportation and large-scale energy infrastructure. Compressed gaseous and cryo-compressed hydrogen storage systems require structural materials capable of safely operating under high pressures, cryogenic temperatures, or a combination of both. In this context, the selection of advanced structural materials is critical to ensuring the safety, durability, and economic feasibility of hydrogen energy systems. Austenitic stainless steels (ASSs), especially AISI 304, are widely considered for hydrogen storage vessels and associated components due to their excellent corrosion resistance, resistance to hydrogen embrittlement, good weldability, and cost-effectiveness. The rapid advancement of hydrogen energy technologies necessitates a detailed understanding of material behavior under service-relevant extreme environments. Although AISI 304 is commonly used in hydrogen-related applications, its mechanical response at sub-ambient and cryogenic temperatures remains insufficiently characterized for reliable material selection and design of next-generation hydrogen infrastructure. This study systematically investigates the low-temperature mechanical behavior of AISI 304 austenitic stainless steel to evaluate its suitability for hydrogen storage and transport systems. Uniaxial tensile tests were performed at temperatures ranging from ambient room temperature (298 K) down to −80 °C (193 K) using a universal testing machine integrated with a controlled cooling chamber. A constant strain rate of 10⁻³ s⁻¹ was applied to isolate the influence of temperature on the mechanical response. The results demonstrate a pronounced temperature dependence of strength and ductility. The ultimate tensile strength increased linearly from 785 MPa at 298 K to 1210 MPa at 193 K, corresponding to a 54.2% enhancement, while the yield strength showed a moderate increase from 690 MPa to 740 MPa (7.25%). Although uniform elongation decreased with decreasing temperature, fracture behavior remained predominantly ductile. Scanning electron microscopy (SEM) analysis of fracture surfaces revealed well-defined dimpled morphologies across all testing temperatures, including cryogenic conditions, indicating sustained energy absorption capability and resistance to brittle failure. These findings suggest that AISI 304 not only maintains but significantly enhances its strength at low temperatures while preserving acceptable ductility, a critical requirement for safe hydrogen storage systems. The novelty of this work lies in the systematic correlation of cryogenic tensile properties and fracture mechanisms of AISI 304 with the performance requirements of hydrogen energy infrastructure. The demonstrated combination of enhanced strength and retained toughness highlights the potential of AISI 304 as a reliable structural material for advanced hydrogen storage applications, contributing to the safe and efficient deployment of hydrogen technologies in future energy systems.