Metal Spray Forming Process Examined Using Mathematical Model Metal Spray Forming Process Examined Using Mathematical Model

Metal Spray Forming Process Examined Using Mathematical Model

  • 期刊名字:钢铁研究学报(英文版)
  • 文件大小:559kb
  • 论文作者:ZHANG Yin,HE You-duo,FAN Jun-f
  • 作者单位:School of Rare Earth,Baoshan Iron and Steel Co Ltd Research Institute
  • 更新时间:2020-11-11
  • 下载次数:
论文简介

IssueMetal Spray Forming Process Examined Using Mathematical Modelonly.Solidification rate f。(3) The temperature distribution in radius was0T> TLneglected.,={ f(T) T,≤T≤Tr(8)1 T RRadius direction:Taking random value ηu,- uro)f(u,)=-'=exp(5)n=A(1-e~ *), Thenξ=-=In|1-4],2c1RRRRwhere u, and σr are the expected value and the vari-K 2'2A’3'3Aance of radius velocity distribution.Circumferential even distribution: ug=01.3 Results(4) Droplets move along z direction:The droplet moves under either the force of gravityn.9lτkτTable 1 Material properties for gas,(6)liquids, and solidsPg1 039 J/kg. Kwhere Su=v(u- -ug)*+(v- vg)"+(w- wg)2586 J/kg.K(5) Temperature change and solidification modelTl1762Kin a droplet with lumped heat capacity method1. 161 6 kg/m3pC。-V,=a(T。- T)A,+one(Ti- T")A, +7 800 kg/ m31675KpH; dfev,(7)1. 78X10-5 N. s/m2lr '6.3X10-3 N. s/m2373 Kwhere V,=≌di, A.=πdk, a= Nu 20.268 W/(m. K)24.2 W/(m. K)Nu=2.0+0.6Re:5sPr2/3, 2Hq_238 961 J/kgYHCNMHG●48●Journal of Iron and Steel Research, InternationalVol.15or the drag. In Fig. 1, the curves that represent theger than dk. For a given flow rate of molten steel,velocities of jets and droplets with different sizesthe number of droplets with different size can be cal-have an intersection point. This means the droplet isculated. Fig. 3 then shows the fraction of a differentaccelerated by the jets gas at the beginning. Aftersize of droplets present within the whole particleboth velocities of gas and droplet become equal, thegroup. The particle sizes from 30 μm to 150 μm re-velocity of the droplet is decreased with the dragpresent the main fractions, such that, the percent-force being dominant.age of particles with too large a size or too fine a sizeis very small. About 2. 5% of the total particles arewith a diameter of 30 μm. The particles smaller than30 μm are the dust created in the spray formingprocess.400,Gas2.3 Position distribution of droplets00On the basis of the function that provides the,30umposition distribution of the droplets, one can deter-00 tmine the data and spread of droplets created in dif-300 umferent locations. It is assumed that droplets are crea-00 Hted in the same plane and evenly distributed over the00.20.40.Fight distance/mFig 1 Velocity of jets and droplets2Statistical Model of Liquid Droplets andTheir MassIt is necessary to know the deposition velocityof atomized droplets, to model and adjust the shape5 0.2of the billet. The mass of liquid droplets depositingon the substrate has a great influence on the shapeand temperature distribution of the billet. In this).20.4 0.5study a statistical model for droplet mass is used toPellet diameter/mmpredict the results and behavior of a large quantity ofFig. 2 Size distribution of atomizing dropletsdroplets on the billet.2.2. 1 Determination of distribution functionThe size, location, and initial velocity of drop-lets created at random will be obtained through theRandom method. Using these results as initial val-1.ues, in conjunction with the motion of a droplet, themotion of mass droplets has been acquired. Afterstatistically analyzing all these results of motion andheat transfer by mass droplets, the initial conditionof droplets deposited on the substrate can be deter-mined.2.2 Size distribution of dropletsIn Fig. 2, the curve indicates the percentage ofparticles within the group in which the radius is lar-Fig3 Fraction of different size of dropletsY中国煤化

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