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Controlled Rolling and Cooling Technology of EH40 Steel

The essence of the controlled rolling and controlled cooling process of EH40 Steel is to combine deformation and heat treatment. Its main purpose is to refine the grains, obtain the desired structure, and improve the mechanical properties of the material. EH40 Steel was once the driving force behind the development of controlled rolling technology. It was the first to adopt the miniaturization method "normalizing treatment method" to produce high-grade thick EH40 Steel. Later, the micro-alloying and controlled rolling process was gradually adopted, so that the produced EH40 Steel had excellent comprehensive mechanical properties and met the needs of EH40 Steel development.

The controlled rolling process is to control the process parameters in the hot rolling process of EH40 Steel, the main parameters of which are heating temperature, deformation amount and deformation temperature, combined with the precipitation of carbonitrides of microalloying elements Nb, V, Ti and other elements, increasing the austenitic the nucleation site of the transformation from solid to ferrite, so as to refine EH40 Steel after phase transformation, and achieve the purpose of improving strength, plasticity and toughness for EH40 Steel.

Controlled rolling of EH40 Steel is generally divided into three stages: controlled rolling in austenite recrystallization region, controlled rolling in austenite non-recrystallized region, and controlled rolling in austenite and ferrite two-phase region.