The Research Of Fiber Laser Cutting Process Of Stainless Steel Sheet

Fiber laser cutting has its unique advantages,such as good cutting quality,high cutting efficiency and high cutting speed.It employs non-contact cutting,thus being widely use.Fiber laser cutting is clean,safe and pollution-free,which has been widely recognized in the market in a few years.Domestic market is stacked with small brands stacked which lack innovation of laser cutting technology.Because of the complex process parameters,in most factories,the technical personnel have to adjust parameters according to their experience,thus displaying low working efficiency.Additionally,many enterprises do not conform to industry standard,thus resulting into the improper control of the product quality.This paper established a finite element model of ANSYS based on the study of present status of laser cutting process at home and abroad,having made the simulation research of the temperature distribution and stressed distribution and their change rule when laser cuts the stainless steel sheet.It also had a scene cutting experiment.With the obtained data,this paper compared with the cutting indexes of the simulation analysis,which verified the reliability of simulation analysis and generalized the cutting rules.Following that,the optimal parameters for cutting the stainless steel sheet have been obtained,which are presented as follows:First of all,according to the established mathematical model of laser cutting energy transfer,the finite element model of the laser cutting process of stainless steel was built by ANSYS simulation software,and the law of distribution and change of temperature has been obtained in use of APDL programming language.The distribution and change law of stress field are obtained by indirect method,and the birth and death element technique is added to realize the simulation of the melting and blowing of the metal when the cutting head moves.It is found that in the advancing direction of the cutting head,both the temperature and the stress showed centralized tendency.The laser transmission is a bucket shaped irradiation in the plate,and there is a phenomenon of the beam concentration in the fiber laser cutting.Secondly,based on the analysis of temperature field by finite element model,the parameters are changed by using the APDL programming language,so as to respectively analyze the influence of cutting speed,cutting power and the plate thickness on the temperature field.Following this,this paper has analyzed its influence on cutting parameters in light of the mechanism.It is concluded that factors such as too fast cutting speed,too small power,or too thick plate can make the temperature received by the material unable to reach its melting point.Therefpre the bottom layer cannot be completely melted,as a result of which,the work piece cannot be cut through.In addition,when the speed is too slow,the inner wall of the slit is continuously irradiated so that the molten metal can be formed into hang slag when it is not blown away in time by the auxiliary gas.Too high power can make the temperature of the cutting area increase sharply,and the melting radius becomes larger,which leads to the widening of the cutting seam and the formation of the droplet.When the plate is too thin,the seam becomes wider and irregular.Finally,the 304 stainless steels with the thickness of 1mm,2mm and 3mm are cut by the fiber laser cutting machine.The height and roughness of the hang slag are measured,and the fringe distance and the slit width are also measured by using the microscope with super depth of field.The experimental results have verified the reliability of the simulation analysis.Additionally,the focus point and power are the main factors affecting the amount of hang slag through the response surface method;the power and plate thickness are the main factors affecting the width of cutting seam;the power and focus point are the main factors affecting the roughness;and the pressure and power are the main factors affecting the fringe spacing.In this way,the optimal parameters of cutting plates are obtained on the basis of simulation and experiments.Meanwhile,the optimal parameters are employed as the process parameters of the simulation analysis and the results show that its model is reliable.