The Study Of Cryogenic Process Of W6Mo5Cr4V2 HSS Taps And Abrasive Resistance Test

With the rapid development of manufacturing industry,the cutting tool manufacturers pay more and more attention to improve the performance of the cutting tool material.The consumption proportion of high speed steel among the cutting tool material is dropped,but the demand of high speed steel thread tools is increased.Screw tap is the main thread cutting tools.The rapid development of tap industries are restricted mainly by life of high speed steel taps.Improving material performance is an important approach to extending the service life of taps.Improving the traditional heat treatment process of taps is importantly significance to the improvement of performance of taps.By W6Mo5Cr4V2 high speed steel(hereinafter referred to as W6 high speed steel)material as the research object,through the traditional heat treatment and cryogenic treatment process research,in the traditional heat treatment process by adding a cryogenic treatment process,the use of orthogonal test design method for quenching temperature,cryogenic temperature,cryogenic times and tempering temperature.The effects of various factors on the mechanical properties and high temperature wear resistance of high speed steel taps were studied.The parameters of cryogenic treatment were optimized to improve the service life of high speed steel taps.The main contents and results of this paper are as follows:(1)According to the study of heat treatment and cryogenic treatment process,combining with the results of this research,using two factors of the traditional heat treatment of quenching temperature and tempering temperature and two factors of cryogenic treatment of cryogenic temperature and cryogenic number as independent variables,using orthogonal table made the testing scheme to heat treatment and cryogenic treatment.(2)The surface residual stress of W6 high speed steel treated by different process was tested by X-ray diffraction method.The influence of cryogenic treatment parameters on the residual stress of W6 high speed steel was obtained.The optimum heat treatment and supercooling process were quenched 1180 ?,cryogenic temperature-155 ?,the number of cryogenic times 3 times,tempering temperature of 560 ?.(3)The mechanical properties of W6 high speed steels treated with different processes were tested.The effects of quenching temperature,cryogenic temperature,cryogenic times and tempering temperature on the hardness,impact toughness and high temperature wear resistance of W6 high speed steel were obtained,and the tap life was tested with the performance of corresponding process of the best sample.It was concluded that the cryogenic treatment process can improve the service life of the tap.(4)The wear mechanism of W6 high speed steel was studied,and the mechanism of wear mechanism was mainly: oxidative wear,adhesive wear and abrasive wear.The cryogenic treatment was mainly due to the wear resistance of W6 high speed steel.The influence of carbides on the distribution of carbides in the material is the main reason for the improvement of the wear resistance of W6 high speed steel after cryogenic treatment.