Research On S890 High-Strength Steel Asymmetrical Thread Turning Chaser Tool And Its Cutting Performance

High-strength steel is widely used in aerospace,machinery,petroleum,civil engineering and other fields due to its superior properties of high strength,high hardness,and high toughness.But at the same time,high-strength steel is a difficult-to-machine material.If ordinary single-tooth thread turning tools are used,it will cause high cutting force,high cutting temperature,and severe tool surface wear,which will seriously affect thread processing accuracy,processing efficiency and tool life.The thread turning of high-strength steel undoubtedly puts forward more stringent requirements on thread turning tools.In view of the characteristics of multi-tooth thread chaser tools with high processing efficiency and long tool life,multi-tooth thread chaser tools are used for thread processing of high-strength steel.Therefore,the key problem to be solved urgently is how to design and optimize the chaser tool structure to achieve high efficiency,high accuracy and long tool life processing of high-strength steel threads.In order to solve this problem,this article aims at the asymmetric thread turning process of S890 high-strength steel,based on metal cutting principles and thread turning tool design theory,using MATLAB,UG,Design-expert,Advant Edge and VERICUT to design asymmetric thread chaser tool,study the influence of chaser tool geometric parameters on cutting performance of the tool,and use BP-genetic algorithm to perform multi-objective optimization of chaser geometric parameters.Specific research work is as follows:1)Preliminary design of asymmetric tooth-type thread chaser tool.Based on the principle of thread turning processing,the processing characteristics of S890 high-strength steel,the definition of asymmetric tooth profile thread and the design theory of thread turning tool,the thesis preliminarily designed an asymmetric tooth-type thread chaser tool,including tool shape,tool material and tool geometric parameters.It provides a preliminary plan for the subsequent optimization of the thread chaser tool.2)Research on cutting performance of asymmetric tooth-type thread chaser tool.Based on the response surface method for machining simulation tests of S890 high-strength steel thread turning,the thesis explores the influence of the blade rake angle,the first tooth height,the blunt radius of the cutting edge,and the interaction of parameters on the cutting force and cutting temperature.It established a regression model of cutting force and cutting temperature,and verified the reliability of the regression model through analysis of variance,laying a foundation for multi-objective optimization of thread chaser tool geometric parameters.3)Multi-objective optimization of geometric parameters of asymmetric tooth-type thread chaser tool.Based on the comprehensive weighting method and entropy method,the thesis establishes a thread chaser tool geometric parameter target optimization model based on main cutting force,cutting depth resistance and cutting temperature.It uses BP-genetic algorithm to perform multi-objective optimization on the comprehensive target,and obtains the optimal comb geometric parameter combination.4)Verification and cutting speed optimization of asymmetric tooth-type thread chaser tool after optimization.The thesis uses Advant Edge machining simulation and thread turning experiments to verify the feasibility and reliability of the optimized tool.Through the singlefactor thread turning experiment,the cutting speed of the high-strength steel asymmetric toothtype thread turning is optimized.In conclusion,this research will provide theoretical basis for the reasonable design of asymmetric tooth-type thread turning thread chaser tool for high-strength steel,and hopefully further improve the cutting performance and efficiency of high-thread chaser tool.