Study On Preparation And Wear Resistance Of Nozzle Matching Parts’s Material

High pressure common rail fuel injection system is the most important component of internal combustion engine for energy saving and emission reduction. Nowadays, environmental awareness is increasingly strong, but the smog is becoming more and more serious in many metropolises, so promotion and application of high pressure common rail technology is becoming more and more urgent. Injector nozzle is the key component of the fuel injection system, however injector nozzle matching parts directly affect the effect of fuel injection, its working condition is adverse, such as its normal operating temperature is generally about 200 ℃, valve needle high frequency sliding, besides the valve needle and the valve body produce high speed crash, on the material it has very high requirements. Therefore, there is an academic significance and practical application value for selecting the material and the heat treatment performance of the injector nozzle matching parts in the high pressure common rail injector nozzle.The main research contents include:(1) From the analysis of the using environment of the high pressure common rail fuel injection nozzle matching parts, then one by one analysis of the mechanical properties of the material requirements, combined with national standards for preliminary selection of existing material in domestic and foreign. Finally, determining the choice of GCr15,18CrNi8 and XW42 three kinds of materials as the experimental object.(2) First, according to the requirements of the experimental sample cutting, surface grinding, blackening the surface and other pretreatments for purchased three kinds of wire rod. Then through selecting defocusing amount of laser hardening, power, scanning speed and other parameters, to use of orthogonal experiment samples of three materials for quenching.(3) By metallurgical microscope, hardness tester, reciprocating friction tester and other equipments to carry out sample quenched hardened layer microstructure, thickness, hardness, wear resistance were observed and tested, to get main performance related data and information of the samples and injector nozzle matching parts, and to analyze these data, and to determine the XW42 material for laser quenching with suitable parameters that can meet the high pressure common rail injector nozzle matching parts performance requirements.