| The cracking and deformation of large forgings are inseparable from the distribution of the flow field during the quenching process,and the flow rate,direction of the flow field and the type of medium will affect the temperature field of the workpiece during quenching,thereby changing the distribution of the structure field,so no matter which part of the problem or Unreasonable will result in unsatisfactory quenching results.It is very important to accurately simulate each link to predict the field volume information.The simulation of each link of quenching can also reduce the cost of using large workpieces for testing.Prioritizing the simulation of reasonable processes can also reduce the rejection rate.The adjustment of the simulation can quantitatively predict the simulation results,and improve the process performance by simulating different parameters.Experimenting with the parameters of the optimal range should be regarded as a very meaningful work.In this paper,15-5PH martensitic stainless steel is used to establish a geometric model of the pump head body with a length of about 1329 mm,a width of about 512 mm,and a height of 587 mm.The geometric model of the water tank is established by (?)2000×1000mm,and the large-scale finite element commercial software FLUENT is used as the calculation platform to establish the water tank.The geometric model,flow field model,temperature field model and structure field model of the pump head body are compared with the influence of two quenching devices and quenching media on the quenching process.The simulated inlet flow rate is 100m/s,150m/s,200m/s Lower the flow field-temperature field-tissue field distribution of the pump head body,determine the appropriate spray parameters,and observe the distribution of the three at the same interface.Get the following conclusions:(1)The curve of specific heat capacity and thermal conductivity with temperature of 15-5PH steel from room temperature to 1300? is obtained by simulation,and the change law of thermophysical parameters of the material is obtained and the curve is fitted for simulation calculation;The starting temperature of the intensification transformation is 117.71°C,and the end temperature is 26.31°C.(2)Establish the geometric model,flow field model,temperature field model,and tissue field model of the quenching process of the pump head body,and obtain the distribution of the three-field coupling at the same interface.(3)The influence of different cooling devices on the uniformity of the flow field is analyzed.It is observed that the flow field of the wall opening device is large,but the flow field is not uniform,and the flow field of the bottom opening device should be uniform.The temperature field cloud diagrams of the flow field of water quenching and oil quenching are compared,and the temperature field of water cooling changes faster than that of oil cooling at the same time.(4)The coupling of the flow field,temperature field and tissue field of the pump head body at the inlet flow rate of the cooling medium in the water quenching process at 100m/s,150m/s,and 200m/s was simulated,and it was found that the pump head body at the inlet flow rate of 200m/s The cooling is the fastest and the tissue field is the most uniform.(5)Verify the accuracy of the simulation results,due to the intense heat exchange in the quenching process,it is impossible to accurately collect the temperature and time change law,so the hardness test is carried out by using the tissue field to take the point to calculate the tissue transformation variable.At the same time,the computer simulates the tissue field transformation under the corresponding conditions to compare the experimental and simulation results.Prove that the mathematical model under this topic is applicable. |
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