Research On Manufacturing Process Of Improving Life Of W6Mo5Cr4V2 High Speed Steel Tap

Compared with the foreign high speed steel taps,the domestic ones service life are shorter.How to improve its service life is of great significance to improve the economic benefit of the enterprise and the manufacturing level of the cutting tool.So taking W6(W6Mo5Cr4V2)high speed taps as the research object,the effect of cryogenic treatment and electrolytic strengthening technology on the wear resistance and life of W6 high speed steel taps is investigated by the method of experimental research,and the wear mechanism of different process is analyzed in order to improve the wear performance and service life of the W6 high speed taps.The main contents and conclusions are as follows:1)Research on the strengthening of the cutting edge of taps.The electrolytic strengthening process of M8 high-speed taps was chosen to obtain different cutting edge radius.Taking H13 as the object to be machined,cutting experiments were carried out to explore the influence of different cutting edge radius on the life of taps.The results show that the tap life is the longest when the cutting edge radius is 17 mm.2)Effect of cryogenic treatment and electrolytic strengthening on high temperature wear resistance of high speed steel.The heat treatment,cryogenic treatment and electrolytic strengthening process of high speed steel samples were worked out,and the high temperature friction and wear test at 500? was carried out.The changes of friction coefficient,wear volume and wear rate before and after cryogenic treatment and passivation were compared,and the effect of cryogenic treatment and electrolytic strengthening on the high temperature wear performance of high speed steel was investigated.The results show that the relative wear resistance of the high speed steel treated by cryogenic treatment is 1.47 times as high as that of the non cryogenic sample.Both the cryogenic treatment process and the electrolytic strengthening process can effectively reduce the friction coefficient.3)Research on microstructure analysis and wear resistance mechanism of cryogenic treatment.The wear scar and carbide precipitation in different process samples were observed by SEM,and the effect of cryogenic treatment on Microstructure and wear mechanism of high speed steel was investigated,and the internal factors for improving the wear resistance were analyzed.The results show that the main reason for improving wear resistance of taps is more fine carbide precipitation in cryogenic treatment.The wear mode of the samples after cryogenic treatment is mainly oxidation wear and slight adhesive wear.The samples without cryogenic wear are mainly abrasive wear.4)Research on the influence of cryogenic treatment,electrolytic strengthening process and their combined processes on the life of taps.Three kinds of M8 taps are made by cryogenic treatment,electrolytic strengthening and cryogenic treatment + strengthening,and the life test of cutting M8 thread holes is carried out by considering the optimum heat treatment,the process parameters of cryogenic treatment and the best radius of the edge.The results show that cryogenic treatment is the main reason for improving the life of taps,and the lifetime is about 4.1 times that of ordinary taps.The life of the tap strengthened by cryogenic + electrolysis has been greatly increased,which is 4.6 times that of the ordinary taps.Therefore,the optimum manufacturing process order of high speed steel taps is the tap rough machining,heat treatment,cryogenic treatment,tap grinding and cutting edge electrolytic strengthening.