Surface Properties Studying Of40Cr By High Current Pulsed Electron Beam

The surface of material is purified at the same time the grain of surface is refinementand comprehensive performance improved after processed by High-current pulsed electronbeams (HCPEB). But the surface of material will appear volcano-pits after processed bythe HCPEB and it has significant influence on the surface roughness. The precision of thegear processing level formulates the7precision in the tooth face roughness requirementsfor1.6μm, tooth root roughness requirements for3.2μm so an important index ofqualifying which is the changing trend of the surface roughness as to whether or not theyare when the different levels of precision parts after the irradiation by HCPEB.This topic is from the part of national natural science funds project "gear surfaceamorphous process and performance study"(Numbers:50775229), chongqing naturalscience fund key project "die surface processing technology and performance by electronbeam"(Numbers:2008BA3014). The main purpose of topic is to research the40Cr steelwhich is commonly used gear after irradiation by HCPEB, the surface performance ofdifferent surface condition of each sample40Cr with changing by parameters of HCPEBprocessing equipment change trend. The main Working contents as followed:(1) The numerical simulation of the temperature field in the process of materialsurface modification by HCPEB. The finite element analysis (FFA) softwareANSYS was applied to simulate the process of modification and obtained thetemperature distribution, the start time of melting, the thickness of the meltedlayer and the range of the heat-affected zone.(2) The various surface roughness40Cr specimens were processed by HCPEB thenuse the stereomicroscope, metallographic microscope and scanning electronmicroscopy (SEM) to analyze and observe the surface organization structure ofspecimens which were the original and different pluses electron beam irradiation.It is concluded that in different initial conditions of electron beam were influenceon the surface organization and structure of40Cr the material surface.(3) The different surface roughness40Cr specimens were processed by HCPEB thenthe comparison and analysis of the surface properties, such as the surfaceroughness, surface micro-hardness changed, and concluded that in different initial conditions of electron beam influence on the performance of40Cr the materialsurface.(4) The different surface roughness40Cr specimens were processed by HCPEB thenconduct the polarization corrosion experiments Research and analyzed thevariation trend of the curve under polarization corrosion on different pulsedelectron beam. It is brought the influence on corrosion behavior of40Cr materialby HCPEB from the variation of Corrosion potential and corrosion current.(5) After the friction and wear experiment between the original samples and differenttimes of irradiation by HCPEB samples then analyzed the results. From theappearance, grinding mark, wear volume and the variation trend of frictioncoefficient to be sure the effect of HCPEB and reductive summing-up the best ofprocessing technology optimal parameters.Based on high and low different surface roughness materials changed after processedby HCPEB then reductive summing-up that the change law about the surface morphologyand properties of materials whit times of irradiation by electron beam. For the HCPEBprocessing technology in the gear surface modification field of applied to provide thetheory basis and the experiment data reserves.