Experimental Study On Cryogenic Treatment Process High-speed Steel Cone Wear Impact

Tapping is one of the most difficult in machining process, because the tapin tapping completely surrounded in the workpiece, tap along the screw threadand the workpiece contact area is large, with the increase of xial force will havea lot of friction, a lot of cutting heat generated when cutting difficult promptlyshed, and the difficulty of chip removal, will soon make the tap wear, tapping isnot efficient. How to reduce the tap wear and improve the production efficiencyis now needs to solve the problem. It had been widely recognized in machineryindustry that the HSS cutting tools for cryogenic treatment can improve itsmechanical properties. Currently, cryogenic treatment less impact study ofhigh-speed steel cone, especially the research finished tap wear cryogenictreatment on the impact of high-speed steel.In this paper, taking W6Mo5Cr4V2HSS finished tap for the study, in orderto reduce the wear of the HSS tap for the optimization goal, with the secondorder response surface model for the design of experiment mode, establish pilotprograms. The HSS cone cryogenic treatment trials and cutting tests, Accordingto the pilot scheme for HSS tap cryogenic processing test and cutting test, Usetool microscope measuring VB of the tap. By single factor method, responsesurface and contour lines and other methods, affecting the tap after cryogenictreatment parameters of knife surface wear and cutting parameters is analyzedand optimized, in order to achieve optimization of cryogenic treatment processand processing scheme, reduce the tap wear, extending the service life of tap.Paper main research content includes:(1) Compare to the Design of Experiment the applicable range andadvantages and disadvantages of various methods, according to thecharacteristics of the test to choose the RSM for test design. At cryogenictemperature, holding time, a spindle speed three factors as the factor, to VB ofthe tap for the response, establish the second-order response surface polynomialequations and test schedule.(2) Cryogenic processing test, measuring the hardness and red hardness of each group taps. Comparative effects of deep cold taps around hardness and redhardness changes, comparing different cryogenic treatment on hardness and redhardness of the tap.(3) Cutting test, measuring the VB of taps after tapping a certain length.Taps will not cryogenic comparison test, Comparison cutting speed and the tapwear changes before and after of cryogenic. Using single factor method analysisthe three factors influence on the wear of the tap, analyzing the change of the taphardness and red hardness on its wear and tear.(4) After using binomial fitting tap cutters wear model equations, theequation of variance analysis and significance test, verify the validity of themodel. Analyze linear effect, cross effect and secondary effects of variousfactors, and draw a three-dimensional relationship between the factors ofresponse surface and contour maps, analyze the impact of the interactionbetween the factors flank wear after the tap, to determine the various factorsoptimum level range.This topic research is supported by“Manufacturing Theory and TechnicalStudy Which Geared to the Needs of Multiple Quality Characteristics IntegratedControl HSS Tap” national natural science foundation of China, the projectnumber is:51275333.