The Technology Research Of Laser Quenching On The20CrMnMo Big-modulus Gears Though The Finite Element Analysis And Test

With the rapid development of laser technology, laser quenching has been widelyused in various parts of heat treatment. Laser quenching is a kind of heat treatmentprocess, through the scanning of laser speckle, work-piece instantly get high and reachthe critical point of martensitic transformation, then the code substrate lower thetemperature quickly to achieve the purpose of quenching. The study of application onlaser quenching in gear is skimp, well the actual application is not too wide. This article,in view of the present domestic commonly used gear steel material—20CrMnMo，makethe research of process and mechanical properties about gear laser hardening.The study is made in a level of the theory of gear laser quenching, and it issummarized of five key technology solutions. Among them, scanning mode is the corewhich determines the overall effect of quenching. The article analyzed differentscanning modes which are suitable for different size gears, then put forward a newscanning mode of big modulus gear. The analysis and formula derivation are made, thenew calculation methods are put forward in a view of the issues about scanning speed,the offset value and incident angle.The preliminary analysis is made though simulating the gear temperature field oflaser quenching process based on the finite element software ANSYS. The3D model ofgear used in ANSYS is imported from UG software and the analysis is simulated on thetooth surface. The operation about the moving of laser spot and the infliction of someload realizes though the programming of APDL language which is directly importedinto the software in order to modify and found errors conveniently. Simulation resultsaccord with the expected results and reflect the excellent characteristics of laserquenching to some extent. According to the simulation results, some certain referencevalues achieved, which laid a foundation for further study.After preliminary analysis,20CrMnMo steels are chose to process gears and thenbegin to test and research. Different sets of parameters (laser power, scanning speed andspot diameter), based on finite element simulation and other research numerical data,are organized and divided, then used to the experiment of processing gears. The furtherprocessing is made using MATLAB software, and the technology parameters on themaximum tooth surface hard are achieved. Then get the best processing parametercombination by observing tooth surface microstructure though SEM device. Analyze gear’s hardness, the depth of hardening layer as well as the conversion relation ofequivalent hardening layer depth treated by the optimal machining parameters.By means of laser hardening gear theory and experimental research, on the onehand, it enriches the theory of laser quenching process and the calculation method oftechnological parameter; on the other hand, it fills the test blank of the laser quenchingabout low-carbon alloy gears after carburizing.