Research On Pressure And Temperature Condition In Rail Beam Blanks Descaling With High Pressure Water

The surface quality, flatness and strength of the rail determine the performance and the service life of the train system. Especially in high-speed railway, we need higher quality steel rail by manufacturing accurately and smoothly to ensure this system operating safely and stably. Modern steel rail mainly adopts the method of universal rolling,therefore, high pressure water descaling is an essential step in the process. Whether the descaling well not only affects the universal rolling process, but also affects the quality of the rail products. This paper studies some characteristics about descaling process including the impact pressure and the heat transfer situation.Firstly, this paper displays the distribution of impact pressure on the rail shaped blank under high pressure by the method of numerical simulation. Because the shape of rail cross-section is so complex and the experimental method is far more perfect that it is difficult to predict the impact situation. Thus, we analyze the impact pressure distribution by separating the rail to different parts to simplify this model with Fluent. Certainly, the numerical simulation is not too complex. In general, the pressure on the point under the nozzle center is the largest and it gradually reduces to the margin; at the same time, it is determined by the section shape and nozzle arrangement.Secondly, this paper uses the same model with the energy equation open to research heat transfer performance. Appling the basic theory about heat transfer and numerical simulating, we obtained the distribution of temperature field about the rail.What’s more, we find the reasons for these phenomena. The distribution of temperature field is just opposite from the pressure field distribution, the heat transfer is the most strongly at the center of the nozzle, so the temperature here is the lowest and gradually increase to two sides; And then, the cross-section shape and the layout of the nozzles have more obvious effects.Finally, we study a simple model to solve the heat transfer coefficient. By using the temperature changing curve on the points below the surface with the depth of 2mm, we solve the heat transfer coefficient through the C programming language. The distribution of heat transfer coefficient is similar to the pressure, the greater impact pressure, the greater heat transfer coefficient is. At the same time, this process is affected by time variation is obvious, we can choose the reasonable time step in order to ensure the accuracy of solution.The study in this paper is an ideal state, but this studying method is with great creativity and we provide a reference for the follow-up study of high pressure water descaling process of rail beam blank.