The Numerical Simulation And Experiment Study On The Forming Of Steel Ball By Longitudinal Rolling

The steel-ball is one kind of metal products and industrial elements which is widely used in machine, metallurgy, mining, building material and light-ind-ustry, primitively consumed in bearing and ball-grinding machine. With the development of the non-ferrous metal industry, electric power and architecture, the need of steel balls is rising rapidly in mining and industry of cement etc. At the same time, the daily necessities and the industrial production make demand on the life-span and the precision of the bearings higher and higher, so the precision and the anti-wear properties of steel-balls demanded is also increasing. The manufacture of ball-billet is the first working procedure of the producing of steel-ball, the quality of ball-billet plays an important role in the quality of steel-ball. So it is necessary and imperative to develop the technolog-y of this method and to enhance the equipment of the producing this kind of products.This study is based on the research of former people. According to the theory of the plastic distortion of the metal, adopted the means of experiment and numerical simulation, taken the longitudinal rolling of the ball as a research object, a new approach of forming the steel ball-billet has been developed. By the medium of establishing simplified model, taking the FEM software Super-Form2002 as an analysis tool, we simulated the flowing of metal in the pass of roller, and obtained the law of flowing of metal, successfully predicted the position where the laps will rise, also put forward some means to solve this problem. On the ground of rolling theory, we established the model of longitud-inal rolling of the steel ball-billet. By the means of experiments, taking the lead-specimen as the workpiece, we explored the optimum pass of the forming ball-billet, and analyzed the influence of forward slip and backward slip to the relation of continuous periodic section rolling. At the same time, we also compared the strongpoint and shortcoming of different rolling method. With the test rolling mill designed by ourselves, we realized the forming of ball-billet, and the result show both the outer-side shape and the quality of the inner microstructure of the balls are satisfactory. As a whole, we lay the theoreticaland practical foundation for the realization of this method in industry.