Optimal Design Of The Horizontal Continuous Casting Devices And Defects Analysis Of Dense Bars

The size range of dense bars which can produce by horizontal continuous casting machine named ZSL-02 is narrow,and the structure of this machine is complex.In order to solve these problems,the optimal design was carried out in this paper.Internal inclusions of ductile iron bars were comprehensive researched.The elements distribution,composition,origins and forming reasons of inclusions were confirmed,and suggestions were given to control generation of this defect eventually.The forming reasons of scar defect was analyzed and factors that affecting formation were discussed.And ultimately effective measures were taken to eliminate scar defects successfully.The new designed horizontal continuous casting machine can meet the production requirements of dense bars with a maximum diameter of 400mm.And the process of horizontal continuous casting simplified,structure of each device is more simple and reasonable.The great mass of inclusions gathered in the position which distance is near 0.75 radius above the centerline of ductile iron bars.And inclusions with large-size are mainly from nodularizing and inoculation treatment.So it can be drawn that the parameter control of nodularizing and inoculation treatment is the key to prevent generation of inclusions.As to the scar defect on surface of dense bars,production practice shows that measures can eliminate it effectively,including raise the temperature of molten iron,ensure the purity of hot metal,increase the drawing speed appropriately,redesign the bottom structure of holding furnace and blocking transverse heat transfer between two graphite molds of crystallizer.