The Research Of Movement Cooling Mechanism Of Hot Rolled Plate

Thermo mechanical control process is of great significance for the development and production of high-performance steel materials and has been widely used in the production of the hot rolled plate.However,part of the controlled cooling plates still exist many problems,including the uneven microstructure and residual stress distribution and the poor stability of the product performance.The key to solving the above problems is to systematically study the complex flow field and temperature field of the medium and heavy plate moving heat transfer process.In this paper,a controlled cooling platform was built through literature research and design,and important process parameters affecting the process of industrial production and controlled cooling were studied.The research contents and results are as follows:(1)The surface cooling area of the high temperature steel sheet impacted by the jet was studied.The boiling characteristics of high temperature steel sheets at different locations in the jet impact process were studied.The transient heat transfer process was analyzed based on the study of the boiling mechanism of the heat transfer process.(2)Design and build a cooling platform to optimize the machining accuracy of the cooling substrate used in the experimental process and the tool accuracy of measuring the temperature to ensure the reliability of the experimental data.The important physical parameters used in the anti-heat transfer process were studied,and the one-dimensional finite difference method used in the calculation of the surface temperature field was analyzed in detail.(3)The important influence parameters of the wetting zone state and heat transfer characteristics during the single-beam moving jet impact hot steel plate were studied.The basic data such as the variation of the wetting area,the change of surface temperature,the heat flux density and the peak of the heat flux density during the heat transfer process are obtained.The important factors affecting the cooling process are the cooling temperature,the water flow velocity,the nozzle moving speed,and the jet flow.The influence of factors such as diameter and jet inclination angle on the heat transfer law was systematically studied.The concept of instantaneous heat loss is proposed to characterize the instantaneous heat transfer capacity.Provide a reference for process design and adjustment in the production process.(4)The state of the wetting region and the heat transfer characteristics during the multiple jet impact on the high temperature steel sheet were studied.Combined with the variation law of the wetting region and the heat transfer data,the heat transfer characteristics of multi-beam moving jets were studied.The results show that the heat transfer capacity of the wetted zone is greatly improved after multiple jet impacts.The maximum value of the peak heat flux density and the instantaneous heat loss decrease with the increase of jet velocity.