Optimal Design Of Water Quenching System Based On Finite Element Analysis

Hot-rolled strip steel is widely used in modern life.Among them,automobile body is one of the main requirements of hot-rolled strip steel.Whether the performance of the body material meets the standard determines whether there is a hidden danger in car driving.The different mechanical properties of hot-rolled strip steel are mainly controlled by the cooling of the strip steel,so the control of the precision of the strip cooling rate and the coiling temperature becomes very important.In this thesis,C-Si-Mn-Cr-Nb strip steel is selected as the research object,and the best solution to the problem of strip edge cracking and tensile strength improvement after cooling is found.From the plan,determine the structure that must be generated when the strip edge is cooled,and the cooling rate to generate the corresponding structure.The strip steel model is established by Solid Works software,and the temperature field of the strip steel cooling process is analyzed in the transient thermal module of Ansys Workbench,and the cooling curve conforming to the cooling process is obtained.According to the different cooling forms of the strip steel,the distribution of the different cooling areas of the water quenching system is initially determined,and the results are as follows:(1)Because the purpose of strip cooling is to avoid the formation of bainite,the minimum cooling rate of strip steel is 40?·s-1.Through the analysis of the temperature field of the first water cooling of the strip,the cooling rates of the edge and the whole are 41.084?·s-1 and 45.784?·s-1 respectively;the temperature field of the second water cooling of the strip is analyzed,and the edge is obtained,The overall cooling rate is 47.540?·s-1 and 49.825 ?·s-1 respectively,and the two water cooling meets the cooling purpose of strip steel.(2)The strip steel is cooled at a constant cooling rate,which is mainly realized by adjusting the cooling water of the water quenching system,and the cooling water flow is mainly realized by the constant pressure control of the water pump.According to the flow value,the cooling water model is established and the pipeline fluid analysis is performed.It is obtained that the pressure and velocity of the upper fluid are 7.9% to 10.3%,1.41% to 3.45% higher than the pressure and velocity of the lower fluid,respectively,and the pressure of the fluid is adjusted upwards,The pressure of the lower fluid can be solved by solving the pressure of the water pump,which can eliminate the influence of gravity on the fluid flow in the header.(3)The first water cooling time of the strip is 14 s,and the second water cooling time is 2s.The operating speed of the strip in the water quenching system is 1m·s-1.The specifications of the main cooling zone and fine-tuning zone of the water quenching system are mainly determined according to the cooling time and operating speed of the strip steel.The specifications of the main cooling zone and the fine-tuning zone are the specifications of the main cooling zone and the fine-tuning zone according to the cooling time.There are 14 cooling sections and 2 cooling sections.The purpose of this division is to cool the strip at a constant cooling rate in water cooling.