2results about How to "Reduce rolling temperature" patented technology

The invention discloses a rolling method for improving the hardness of a steel rail with standard strength. The production process comprises the following steps: molten iron in a steelmaking process, converter smelting, LF (ladle furnace) refining, VD (vacuum degassing) and continuous casting to ensure the purity and component uniformity of molten steel; rolling and subsequent processes: heating by a stepping furnace, descaling by high-pressure water, rolling by a universal rolling mill, cooling and pre-bending by a cooling bed, straightening, carrying out ultrasonic flaw detection, processing, checking and warehousing; the steel rail comprises the following chemical components in percentage by mass: 0.81-0.86% of C; s : 0.52%-0.59%; mn: 1.17 to 1.25%; less than or equal to 0.020% of P; less than or equal to 0.020% of S; 0.23 to 0.28% of Cr; 0.03 to 0.05 percent of N ; and the balance Fe and impurities. The low-cost and high-quality high-speed steel rail steel is prepared by optimizing the chemical components of the steel grade and customizing the controlled rolling and controlled cooling process, and the hardness, strength and toughness of the high-speed steel rail steel all meet the American standard requirements.

The application discloses a method for controlling the bainite structure component of steel, which comprises the following steps: S1, controlling the parameters of the hot rolling process of the steel billet, including reducing the opening rolling temperature by 50-100 DEG C, reducing the rolling speed by 3-10%, and water cooling between the rolling mill racks to form a low final rolling temperature; and S2, after the final rolling is completed, forcibly cooling the rolled piece at a cooling speed of 50 DEG C / s-300 DEG C / s, so that the temperature of the rolled piece rapidly enters the two-phase region or even below the Ac1 line, thereby slowing down or inhibiting the dynamic recrystallization process of the deformed austenite, and making the cooling curve "chase" the continuously right-moving pro-eutectoid ferrite line. By adopting the technical scheme of the application, a significant amount of ferrite component can be obtained for the bainite steel under the hot rolling condition, that is, a ferrite+bainite complex phase structure with different proportions is formed, so that the strength and the toughness and plasticity of the steel can be regulated in a large range.