Tempering Time‐Dependent Microstructural Evolution and Mechanical Property Modulation in AH460 Marine Engineering Steel

The effect of the short rolling–quenching–tempering (R‐Q‐T) process on the microstructural evolution of AH460 marine engineering steel was systematically investigated through high‐temperature deformation experiments and heat treatment analyses. Theoretical calculations and multiscale characterization were conducted to quantitatively evaluate its microstructure and precipitation behavior. A thermodynamic‐kinetic model was established to analyze V(C,N) precipitates in ferrite, identifying 600°C as the optimal holding temperature. The microstructure and phases were examined using optical microscopy, X‐ray diffraction, and transmission electron microscopy, where compositional and diffraction analyses confirmed the precipitate as V(C,N). The results revealed that the short R‐Q‐T process refined and homogenized the microstructure, while the size and density of precipitates increased with tempering time. The V(C,N) phase contributed to grain refinement during deformation and cooling, and enhanced precipitation strengthening at room temperature. The synergistic action of these mechanisms improved the mechanical properties of AH460 steel, demonstrating that the short R‐Q‐T process is an effective route to achieving high strength and structural uniformity.