Research On Complex Brass Performance Based On Procast Simulation Analysis

With the development of high-strength wear-resistant brass,the factory puts forward higher requirements on the service life and mechanical properties of the rolling mill nut.The matrix composition,grain size and precipitate phase composition of copper alloy constitute the key factors affecting the tensile strength,hardness,elongation,casting properties and cutting performance of brass;at the same time,the factory put forward requirements for the improvement of the casting process of high-strength wear-resistant brass.In order to save costs,it is imperative to introduce computer finite element simulation in order to reduce the amount of entrainment and inclusions generated during the casting process.Therefore,the study of high-zinc equivalent,low-strength wear-resistant brass with high brass strength,high strength,high hardness and good elongation,and the use of software simulation combined with actual production,has become the development trend of the current rolling mill nut.This paper designs the chemical composition and production process of high-strength wear-resistant brass,and uses the intermediate frequency furnace and factory casting system to prepare brass ingots,the metallographic structure of brass ingots with different compositions was analyzed by using metallographic microscope,scanning electron microscope,spectroscopy instrument,Vickers hardness tester,universal testing machine and friction wear ring.The paper studies the matrix structure and hard precipitated phase of brass with different compositions and different cooling rates,analyzes the influence of zinc equivalent and metamorphic elements on the materials,and determines the mechanical properties such as hardness,tensile strength and elongation of the materials.The article also combines the simulation software,proposes a new improved casting process,establishes the casting system simulation model,and studies the effects of different casting speeds on the material under the new casting system.Studies have shown that:brass materials reduce copper content,increase zinc equivalent will produce more ? phase,improve brass strength and hardness,reduce plasticity,adding Mn?Al,element to the brass will melt into the matrix structure.Adding Si?Fe and Ti will form a white hard wear-resistant phase dispersion and improve the wear resistance of the brass.The addition of an appropriate amount of Si promotes grain nucleation.The casting system was modified and designed by Pro cast casting simulation software.The bottom casting can effectively increase the density of the casting.Adding a heat-insulating riser can effectively fill the material and improve the yield;during the pouring process,the flow rate of the key points of the runners was stable.The actual production verification was carried out by the factory with the pouring system,and the performance of the obtained castings was significantly stable.The best process plan is:Cu content is 53wt.%,Zn content is 39wt.%,Mn content is 4.5wt.%,Pb content is 0.5wt.%,Al content is 1.5wt.%;adding metamorphic element is 0.1wt.%Al-20Si;The optimal pouring system is metal bottom casting,the number of runners is ten,the pouring temperature is 1200?,and the pouring speed is 3kg/s,cooling rate 30K/s,the ?+? two-phase brass can be obtained by pressing the nut using the casting process and the mill obtained by the formula.The hardness reaches 130HV,the tensile strength is 510MPa,and the elongation is 13%,which satisfies the service conditions of the rolling mill nut.