Experimental Research On Cutting Hardened Die Steel With Coated PCBN Tool

Hardened die steel is a material with high strength,high hardness,good wear resistance and strong impact resistance.It is widely applied in automobile manufacturing,home appliance manufacturing,and the manufacturing of various medical products.The hardened die steel is a typical difficult-to-machine material,which will cause problems such as high cutting force and fast tool wear during processing.In modern processing technology,"turning instead of grinding" is often used to process hardened die steel.In order to ensure the cutting quality,it is necessary to select suitable tool material and reasonable cutting parameters to meet the needs of engineering practice.Coated and uncoated PCBN tools are applied to cut hardened die steel.Cutting force,surface roughness,tool wear and chip morphology are analyzed in depth to determine the more suitable tool material,cutting amount and nose radius parameters for cutting hardened die steel.The cutting force and surface roughness are reasonably predicted and analyzed through the establishment of mathematical models and finite element simulation.The main work is summarized as follows:(1)The reasonable tool materials for cutting hardened die steel are studied.The results show that the cutting force and surface roughness produced by coated and uncoated PCBN tools for cutting hardened die steel are not much different.But the tool life of coated PCBN tool is better,so it is determined that the coated PCBN tool is a reasonable tool material for processing hardened die steel.(2)The cutting force,surface roughness and chip morphology of coated PCBN tools in hardened die steel are studied,and the reasonable cutting parameters and tool nose radius parameters are determined based on this.The results show that when the cutting speed is125.6m/min,the feed rate is 0.10mm/r,the back-cutting amount is 0.05 mm,and the nose radius is 0.4mm,the cutting force generated by the cutting process is the smallest and the best machining quality can be obtained.(3)The prediction model of cutting force and surface roughness is established.The prediction model of cutting force and surface roughness is established by multiple regression least square method and least square support vector machine method.Comparing the prediction results and test results,it can be seen that the prediction model established by the least square support vector machine method has smaller errors,the average error is about 5%.(4)The finite element simulation model of the cutting process is established and the simulation analysis of the cutting force is completed.The results show that the average error of the cutting force simulation using Deform-3D is about 7%.This method can make a reasonable prediction of the cutting force generated during the cutting process.