Research On Optimization Of Pass Composition Parameters Of High-speed Wire Rod

High-speed wire rod has the characteristics of small section,long length,and high dimensional precision and surface quality requirements.The current market requirements for high-speed wire are still gradually improving,and the optimization and upgrading of pass system is the key to improve the quality of wire.In this paper,the existing pass system of high-speed wire rod is studied and the optimization direction is sought,so as to determine the reasonable pass system and provide reference for the upgrade of wire pass system.Combined with the on-site production process,the ?5.5 mm high-speed wire rod pass system was taken as an example,and the rolling model was established by using the finite element method.The analysis shows that the arc radius of oval hole in the current pass system is larger,the rolled piece is squat,and the size of the rolled piece in oval hole is asymmetrical.In the stage of pre-finishing rolling and finishing rolling,the filling degree of pass is not reasonable,and there is the phenomenon of under filling or overfilling,and the rolled pieces are easy to appear ears,which leads to the quality problems such as folding in the subsequent rolling;In the reducing and sizing stage,the deformation distribution of rolled pieces is unreasonable,and the finished product size is seriously overcharged,which results in the failure of product ovality to meet the market requirements.The three-dimensional coupling numerical simulation of oval-round pass elements in wire production was carried out by means of control variables,and the influence law of oval pass radius,roll gap,oval pass width-height ratio,feed fluctuation and round pass expansion factors on rolling process was analyzed.The results show that the radius of the oval hole and the roll gap can effectively change the width of the rolled piece in the subsequent round hole.Reducing the width-height ratio of oval pass is beneficial to improve the surface deformation uniformity of rolled pieces.The oval-round-oval-round pass system has a accommodate space to the size fluctuation of the supplied rolled piece,which can provide a reference for the sharing of the pass system.The expansion mode and angle of the round hole will affect the size and surface deformation of the rolled piece.The influence rule of pass elements lays a foundation for pass elements optimization.According to the influence rule of pass elements on rolling process,the optimization scheme of pass was put forward on the basis of existing pass system.The simulation model of the new pass system was established to analyze the filling degree of pass and the surface deformation of rolled pieces.After confirming the reasonableness of the pass shape,the roll groove processing,the roll and the guide are ready to start the industrial test rolling.The head and tail of the test rolled products were sampled,and the diameters and hot-head forging were tested.The final products were determined to meet the production requirements of GB/T 14981-2009.This optimization rule can provide a reference for the optimization of other pass systems.