Quenching Internal Stress Evolution and Shape Control in Gigapascal Ultra-High-Strength Martensitic Steel

Gigapascal ultra-high-strength steel holds significant applications in the energy and military sectors. Such steel is typically produced through quenching and tempering processes. However, during quenching, issues such as excessive internal stress often lead to significant deviations in flatness, thereby reducing product precision. This study adopts an approach integrating theoretical and practical methods to develop a control technology for achieving high flatness in gigapascal ultra-high-strength martensitic steel. Firstly, finite element simulation was employed to establish a temperature-phase transformation-stress coupling model for the quenching process of gigapascal martensitic steel. The study investigated the deformation behavior of steel plates under unilateral cooling, the influence of dynamic martensitic transformation on internal stress, and the effects of plate thickness and water ratio. This revealed how quenching process parameters affect the internal stress and deformation of steel plates. Based on theoretical calculations and considering on-site equipment conditions, industrial production line commissioning was conducted, which significantly reduced the quenching internal stress of gigapascal ultra-high-strength martensitic steel and greatly improved the flatness of the steel plates. The results surpassed those of international companies such as Sweden’s SSAB and other domestic enterprises, achieving an internationally leading level.