Effect Of Carburizing And Grinding Processes On The Surface Microstructure And Properties Of 16Cr3NiWMoVNiE

As components in special service environment,engine gears need to meet higher requirements in performance,and performance is closely related to surface state.16Cr3 NiWMoVNiE as a material with good strong thermal performance,has a key role in the engine gear,can withstand a huge load and adapt to the harsh service environment,but gear failure occurs from time to time,such as due to high carbon content caused by cracking after grinding,Too low carbon concentration leads to low surface hardness and lack of wear resistance,resulting in tooth fracture and other failures.After grinding,cracks and grinding burns appear on the surface of the workpiece.In the process of gear surface strengthening,carburizing and grinding have great influence on gear surface performance.In order to further understand the influence of carburizing and grinding on the surface structure and properties of material,the gear material 16Cr3 NiWMoVNiE was taken as the research object,and the gear sent for inspection was compared.The carburizing heat treatment test and grinding test were carried out respectively,and the influence of different process parameters on the surface structure and properties of material 16Cr3 NiWMoVNiE was discussed.In order to improve the test efficiency,the simulation carburizing process was selected in the carburizing process.In order to discuss the influence of grinding process on surface properties under different surface carbon content,the sample was prepared by solid carburizing method.This article first to carburizing gear steel material simulation test,to explore the different carbon potential and carburizing and quenching temperature on the material surface carbon concentration distribution and the influence of the microhardness,then pack carburizing experiment was carried out,after carburizing treatment on the microstructure of the samples analysis,microhardness and thick of carburized layer,and the carburized samples are three factors three levels orthogonal grinding experiment,The surface morphology,surface roughness and surface grinding burn of the grinding samples were detected.The effects of different grinding process parameters on the surface structure and properties of materials were discussed through orthogonal analysis,and a more appropriate grinding process was determined comprehensively.The main research contents are as follows:(1)Through the carburizing simulation test,with the increase of carbon potential and carburizing temperature,the carbon content on the material surface and the depth of the carburizing layer gradually increase.The quenching temperature has little influence on the carburizing results.The comparison between the simulation results and the hardness distribution of the gear shows that the simulation experiment is reliable.Through solid carburizing test to get higher as the carburizing temperature and time on the rise,material surface carbide grades gradually increases,the surface carburized layer distribution gradually thickening,makes by microstructure compared with the analysis of gear,found from surface to the core zone,both by carbide,carbide and martensite mixed zone and matrix of martensite zone;(2)the preparation of solid carburizing carburizing grinding processing sample,found that when the carbon content is small,individual bureau minister cracks after grinding,with carbon content increasing,the crack was gradually changed from less long crack to more short fatigue cracks,according to the number of crack will crack situation quantitative analysis,found that periods of low carbon,influence the crack situation of grinding parameters is the feed rate,More carbide is the grinding wheel speed.It is found that the roughness fluctuation is the smallest under the condition of ⅱ carbide and the largest and coarser under the condition of ⅲ carbide.Through analysis,it is found that the feed speed has the greatest influence on the surface roughness,and the roughness value is the smallest under the conditions of(4)and(5)grinding.(3)On the whole,the more carbides on the surface,the greater the proportion of grinding burn area.The analysis of grinding burn area shows that the higher the grinding speed,the more serious the grinding burn area.According to the experimental results,in order to obtain smaller roughness and less grinding burn area,it can be known that(4)and(5)grinding processes are the optimal processes.