Numerical Simulation Of Three Roll Cross Rolling Process On Hollow Drill Steel

Hollow drill steels which act as drilling steel rods are named rock drill steels for short, Nowadays, the hot piercing and hot stretching method is the main method of processing rock drill steels in our country. In comparison with the hot piercing and hot stretching method, the hot piercing and hot rolling method is more promising, because the method is more efficient and their finished products'life-span is longer.In the past, research about hollow drill steels which act as drilling steel rods were mainly converged in strain and stress in work,life-span estimate,hot treatment technics as well as the choice of material. Few people researched rock drill steels about the process of rolling and they often adopted experimental or qualitative methods. The research on the influence law of the deformation and the microstructure of the rolled piece is still in its initial stage.Base on rigid-plastic FEM method of the paper, the process of three roll cross rolling of hollow drill steel is simulated by using DEFORM finite element analysis software, research and analysis the change law of the rolling process and the microstructure of hollow drill steel.The historical research on the rock drill steel is reviewed at first, the research and development of the three roll cross rolling and the microstructure simulation is introduced simply; Expounds systematically the basic theory of rigid-plastic FEM, gives the rolling principle of the three roll cross rolling and the theoretical basis of the microstructure simulation; Then, rock drill steels rolling processes with different roll pass variables have been simulated by using DEFORM finite element analysis software, research and analysis the deformation law of rolled rock drill steels, between the different reducing diameter amount, feed angle and diameter of mandrel, obtained strain,strain rate and other field variables in the deformation zone,also obtained the change law of rolling load and rolling torque of the roller, the relationships between the technics variables of rolling and the microstructure of rolled piece are analyzed as well.At last, analyse comparatively the deformation and the microstructure of the rolling without mandrel and the rolling with mandrel of hollow drill steel.