| The solidification process exists widely in metallurgical process,which affects the microstructure of steel,which determines the properties of steel,and also affects the segregation of steel.Grain refinement can solve the above problems.With the rapid development of iron and steel industry,the traditional method of solidifying fine crystal is no longer suitable for the existing metallurgical development,so it is necessary to develop new methods of solidifying fine crystal.Based on the current mainstream of electromagnetic stirring solidification of fine grains,the sources of refined grains in the solidification process of metals are not all formed by electromagnetic stirring.In addition,electromagnetic stirring devices are generally large,and it is inconvenient to use and maintain in the later period.In addition,there are also inhomogeneity in electromagnetic force.On this basis,the electromagnetic energy fine crystal technology is proposed,which produces different electromagnetic effects in different electromagnetic technologies.For the solidification process of steel,low-frequency electromagnetic energy refining grain technology is relatively feasible.In this paper,high manganese steel(ZGMn13)is taken as the experimental research object to carry out preliminary experiments on solidification fine grain technology of low-frequency electromagnetic energy.This experiment consists of heating device,smelting device,electromagnetic energy device and temperature measurement and other ancillary devices.During the experiment,optical microscope was used to observe the morphology of solidified microstructure,ICM and Origin software were used to calculate and calculate the grain size of solidified microstructure,and the segregation degree of elements in different parts of solidified microstructure was measured by spectrometer.Experiments under different magnetic field frequency is analyzed,from the bottom of the ingot casting 10 mm,100 mm,200 mm and 1/2 of ingot casting the core radius in grain size,found that the grain size is much better than that at the bottom of ingot casting,under20 HZ of ingot casting the core minimum grain size is about 103 um,compared with the untreated grain size 114 um,refinement,9.6% in ingot at 1/2 radius,with increasing magnetic field frequency,different ingot casting parts grain size gradually decreases,andunder 60 HZ is 200 mm from the bottom of the ingot maximum levels in detail,refinement of about 32%.The central shrinkage cavity of the ingot was analyzed experimentally,and it was found that the area and depth of the central shrinkage cavity of the ingot gradually decreased with the increase of magnetic field frequency,reaching the minimum at 60 HZ,approximately 60% less than that of the untreated central shrinkage cavity.Experiment analyzed the ingot segregation,each element separately at the edge of the ingot casting department,1/2 radius,heart,even take along diameter direction,found that after processing negative segregation of C and Si elements with magnetic treatment and untreated low volatility,and add after magnetic treatment Mn element reduces the negative segregation degree,on the segregation index,C segregation index compared with magnetic treatment when not stable fluctuations near the 1,among them,the center position to reduce the most obvious decrease about 0.138.The segregation index of Si was concentrated between 0.997 and 1.007 after magnetization,while the segregation index of Mn was stable around 1 after magnetization.It can be seen that electromagnetic energy can obviously change the segregation of the ingot and make the components in the solidification process more uniform.Under the same solidification condition and the same magnetic field condition,the electromagnetic energy has a positive effect under the low-frequency parameter,and the average power consumption is less than the average power consumption of electromagnetic stirring technology.The existing experimental design has a good application prospect in the steel casting process.In order to enhance the refinement effect of low-frequency pulse electromagnetic energy,a new type of electromagnetic coil combination mode is designed,and the industrialization is gradually completed. |
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