The article presents the findings of a study on the machining of 10 mm thick Hardox 400 steel plates using the CO
laser. The purpose of the investigation was to investigate the relationship between ...the entropy and the hardness of machined surfaces. For this purpose, a new mathematical model is established to estimate the entropy, and its influence on the hardness is determined. The mathematical model is statistically and experimentally validated. An entropy variation ΔS = -330 mJ/K between 2 K is found, causing a decrease in hardness compared to the standard value. The influences of input parameters (laser power, cutting speed, and auxiliary gas pressure) on hardness are determined. It is demonstrated that the surface hardness is strongly influenced by the auxiliary gas pressure. The combination of laser power
= 4200 W with gas pressure
= 0.45 bar at average cutting speed
= 1400 mm/min leads to a hardness of 38 HRC, extending the life and wear resistance of the cut parts.
The use of laser technology for materials processing has a wide applicability in various industrial fields, due to its proven advantages, such as processing time, economic efficiency and reduced ...impact on the natural environment. The expansion of laser technology has been possible due to the dynamics of research in the field. One of the directions of research is to establish the appropriate cutting parameters. The evolution of research in this direction can be deepened by determining the efficiency of laser cutting. Starting from such a hypothesis, the study contains an analysis of laser cutting parameters (speed, power and pressure) to determine the linear energy and cutting efficiency. For this purpose, the linear energy and the cutting efficiency were determined analytically, and the results obtained were tested with the Lagrange interpolation method, the statistical mathematical method and the graphical method. The material chosen was Hardox 400 steel with a thickness of 8 mm, due to its numerous industrial applications and the fact that it is an insufficiently studied material. Statistical data processing shows that the maximum cutting efficiency is mainly influenced by speed, followed by laser power. The results obtained reduce energy costs in manufacturing processes that use the CO2 laser. The combinations identified between laser speed and power lead to a reduction in energy consumption and thus to an increase in processing efficiency. Through the calculation relationships established for linear energy and cutting efficiency, the study contributes to the extension of the theoretical and practical basis.
Laser cutting has experienced a sharp development in recent years due to the advantages it implies in industrial production, the most important being: great diversity of processed materials, reduced ...cutting time, low processing cost, small percentage of removed material, and low impact on the natural environment. The problem of energy has become acute in the last year, so a new direction of research has taken shape, consisting of the optimization of the high energy consumptions involved in laser cutting. The objective of this research is to develop a computational and experimental model to estimate the melting efficiency. Additionally, the research seeks to establish some mathematical relationships that describe the law of variation of the melting efficiency depending on the input parameters in the CO2 laser cutting. The experimental determinations were carried out on Hardox 400 steel plates of 8 mm thickness. The input parameters were laser power, assist gas pressure, and cutting speed. The experimental data were statistically processed, and the results were verified with the Lagrange interpolation method. It was found that the maximum melting efficiency is influenced mainly by laser power (F = 3.06; p = 0.049), followed by speed and pressure. The results obtained show that the melting efficiency varies in the range (13.6–20.68) mm3/KJ. The maximum value of the melting efficiency (20 J/mm3) was obtained when the laser power was 5100 W, the cutting speed 1900 mm/min, and the gas pressure 0.5 bar, and the minimum efficiency under conditions of speed setting at 1700 mm/min and laser power of 5000 W. Linear and quadratic regression models were established to estimate the global mean efficiency according to two independent variables that act at the same time. The established calculation relationships contribute to the improvement of the literature and constitute a tool for practical applications. The results obtained allow the modeling of cutting parameters and the optimization of production costs in industrial processes that use laser cutting.
This paper presents an experimental research that proposes to determine the influence of process parameters on CO2 laser cutting of 8 mm thick Hardox 400 steel, for which Kerf has a minimum value. ...The experimental research was conducted according to a complete factorial plan with laser power, assistant gas pressure and cutting speed as the input parameters, and cutting width as the dependable variable. The Design of Experiment (DOE) consisted of 27 references and was completed with four replicas to determine the variation of the Kerf average. Functional, linear and quadratic relations were determined, which describe the Kerf dependence on the cutting parameters in order to establish the most influential parameter. The results show that the independent parameter with the most significant influence was the laser power, with minimum Kerf obtained if the laser power and the assistant gas pressure were adjusted to average values. The interaction between laser power and auxiliary gas pressure at constant cutting speed was investigated to improve Kerf and reduce the laser processing cost. The study offers the right combination of process parameters that leads to a minimum value of the cutting width.
The study on the roughness of Hardox cut laser parts is exploited in this article ranging from input parameters (laser power, pressure, cutting speed) to a Taguchi reduced to 9 references and then ...replicated under the same conditions 4 times. For the experiment, a fractional factorial plan L339 was chosen for three experimental parameters (P, v, p), each varied at 3 distinct levels. The blank used was HARDOX400 steel sheet with a thickness of 10 mm. This thickness is suitable for the study of several parameters that characterize the quality of laser cut parts: slot width, taperedness, flange roughness, dimensional precision. With the help of Statistica 7, the prediction and correlation formula of the influence factors were highlighted. DOE and SSM were used to obtain roughness while maintaining a constant parameter - laser power and simultaneously varying the pressure and cutting speed. It is found that pressure is a dominant influence factor.
The model was introduced by Malkin (ECM) to describe the behavior of rare earth metals (RE) andtransition metals (TM) used as an impurity ion crystal field of ligands belonging to the crystal (host ...matrix).Thecalculation is quite easy for those who apply irreducible tensor operators MAPLE programming introduced byMalkin.
Soft steels are used in the processing and fabrication of parts due to corrosion and wear resistance. In the manufacturing technology of these products, a circular cutting experiment was designed ...where disks were obtained at various values of the laser input parameters, cutting speed, gas pressure, laser power, focal position. The present study is based on the circular cutting of the parts made of OL 37 material. The measurements of the discs indicate different and close values from one reference to another, respectively the conicity of the made parts. It is proposed to treat the theoretical aspects related to the stationary and dynamic piercing speed of the laser, the geometry of the piece, the geometric flexibility in determining the deviation from the circularity, the simulation of the addition of melting x depending on the melting angle α, of the geometry of the molten front of the laser leaving from the tip of the laser spot. The method of determining the laser speed in the cutting process is calculated and discussed, the deviation from the circularity, the angle of deviation, the problem of variation of the deviation x from the rectangular dimensional accuracy of the slit due to the laser laser CO2 melting.
LASER CUTTING OF SOFT STEEL IN INDUSTRIAL PARTS MANUFACTURING Constantin Cristinel Gîrdu; Mircea Viorel Drăgoi; Mihaela Mileșan ...
Analele Universităţii "Constantin Brâncuşi" din Târgu Jiu: Seria Inginerie,
11/2019, Volume:
2019, Issue:
2
Journal Article
Peer reviewed
Open access
An interesting study on the cutting of flexible steel using the CO2 laser is discussed in this paper. We used a rigorous mathematical model resulting from the experiments performed to determine the ...cutting speed, the deviation from the circularity of the disks, the geometry of the slit under more efficient conditions. I used a complete plan to make the cut. The focal position influences the cut, respectively the measured sizes. In the measurement process we used for Kerf the scanner and the electronic micrometer, and for the laser-cut surfaces the roughness meter and the durometer. The cutting process has been improved due to the use of the mathematical model. They were highlighted and calculated the cutting speed, the conicity due to the elliptical shape of the cut piece geometry when debiting the piece, conditions for minimizing the slit / cut channel. The relationships resulting from the part geometry indicate the circularity, data for the calculation of errors, the speed of work in stationary and dynamic piercing. The study is complex and varied because it can be supplemented with statistical data processing programs. The results of this article indicate the deviation from the circularity, the ellipse that approximates the piece, the composition of the speeds, the geometric modeling of the piece. All these relationships obtained accurately and accurately reproduce the dimensional accuracy of the pieces. By choosing the formulas expressed we can validate the calculation by comparing the measured values of the output parameters.
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