Theoretical Foundations of the Hot Stamping of Ultra-High-Strength Boron Steel: The Case of B1500HS with 22MnB5 and BR1500HS as Benchmark Grades

The hot stamping of boron-alloyed steel integrates forming with in-die quenching and is a core route to 1500 MPa class automotive safety components, yet its parameter design still lacks a unified theoretical basis. This article critically reviews the theoretical foundations of the process and establishes a framework covering four pillars: analytical parameter-design models (heating time, forming force, springback, and die cooling-channel sizing); hot-plastic-deformation mechanisms interpreted through a molecular dynamics (MD)–discrete dislocation dynamics (DDD)–crystal plasticity finite-element (CPFE) multi-scale hierarchy; phase transformation kinetics extended by a Ginzburg–Landau phase-field description of variant selection; and heat transfer with thermo-mechanical coupling. B1500HS is adopted as the primary grade, with 22MnB5 and BR1500HS serving as benchmarks for cross-validation. The calibrated hyperbolic-sine Arrhenius model yields a deformation activation energy of 245.4 kJ·mol−1, consistent with dislocation-climb-controlled deformation of austenite, and a worked cooling-channel example (380 kW heat load) confirms engineering applicability. The framework provides quantitative theoretical boundary conditions for process optimization, die design, and quality evaluation of hot-stamped components.