High-boron steel 304B7 has been selected as International Thermonuclear Experimental Reactor vacuum vessel in-wall shielding material. Due to the brittle fracture issues of high-boron steel, there are still many challenges to overcome in engineering-scale production. Based on the preparation process of engineering applications, it is necessary to explore the material preparation of hot isostatic pressing (HIP) and melting-casting. In this study, sample 304B7-A was prepared by HIP, and sample 304B7-B was prepared by melting-casting. The research focuses on the morphology of precipitation and the evolution of matrix texture, analyzing their relation to the macro-mechanical properties of high-boron steel. This study comprehensively analyzes the results of Vickers hardness, tensile test, scanning electron microscope, and electron backscatter diffraction. The findings indicate that the phases of 304B7-A are finer and more dispersed, resulting in a synergistic effect of grain refinement and grain boundary pinning, which significantly enhances the mechanical properties. Texture analysis reveals that during plastic deformation, γ-Fe grains rotate towards the {110}<111> ∥ loading direction, and the {110}<001> texture is effectively retained in the samples. These findings provide theoretical foundations for optimizing high-boron steel’s mechanical properties, and make great significance for expanding its engineering applications in the nuclear industry.
This paper investigates how the manufacturing process affects the microstructure and mechanical properties of high-boron steel, a material used in nuclear reactors. It compares samples made by hot isostatic pressing and melting-casting, finding that the finer, more dispersed precipitates in the pressed sample lead to better mechanical performance through grain refinement and grain boundary pinning.