The Effect of Focal Distance and Type of Auxiliary Gas on Cut Width in CO2 Laser Cutting of Stainless and Mild Steel Sheets

Subject Areas : advanced manufacturing technology

Hossein  Taheri ¹ (Modern Manufacturing Technologies Research Center (MMTRC) Najafabad Branch, Islamic Azad University, Najafabad, Iran)
Hamid  Zarepour Firouzabadi ² (Modern Manufacturing Technologies Research Center (MMTRC) Najafabad Branch, Islamic Azad University, Najafabad, Iran)
Majid  Hashemzadeh ³ (Modern Manufacturing Technologies Research Center (MMTRC) Najafabad Branch, Islamic Azad University, Najafabad, Iran)

Received: 2018-06-18 Accepted : 2018-12-09 Published : 2018-12-01

Keywords: St37 Mild Steel, Cut Width, 304L Stainless Steel, CO2 Laser Cutting, Auxiliary Gas,

Abstract :

Lens focal distance and auxiliary gas type utilized in CO2 laser cutting are two important parameters affecting process measures such as cuts width and quality at desired cutting speeds. This research work focuses on cuts width and quality in CO2 laser cutting with a power of 4000W on two types of steel sheets at different focal distance values and using different types of auxiliary gas. The effect of focal distances of 5” and 7.5” as well as utilizing oxygen and nitrogen as auxiliary gas on cut width and quality in 304L stainless steel and St37 steel sheets were investigated. The size of cut widths was measured using an optical microscopy. The results demonstrate that cuts performed at the focal distance of 7.5” are wider than those created at the focal distance of 5”. It is also observed that with increased workpiece thickness, the use of focal distance of 7.5” is more feasible because cuts are faster; need lower laser power, and use less amount of auxiliary gas. When using oxygen as auxiliary gas, the main factor affecting the cutting efficiency is the oxidation reaction, whereby oxidation energy is added to laser power which results to an increased energy level in the cutting region. This means that using oxygen as auxiliary gas makes it possible to cut thicker sheets at higher cutting speeds as compared to that of nitrogen. However, when using oxygen as auxiliary gas, the quality of cuts appears to be lower and their width larger as compared to cuts performed by nitrogen auxiliary gas.

References:

[1]     Oroumand, Z., Laser and its Applications, DaneshParvar Pub, 2006, pp. 1.

[2]     Librera, E., Riva, G., Safarzadeh, H., and Previtali, B., On the Use of Areal Roughness Parameters to Assess Surface Quality in Laser Cutting of Stainless Steel with CO₂ and Fiber Sources, Procedia CIRP, Vol. 33, No. 1, 2015, pp. 532-537.

[3]     Tahir, A. F., Aqida, S. N., An Investigation of Laser Cutting Quality of 22MnB5 Ultra High Strength Steel Using Response Surface Methodology, Optics& Laser Technology, Vol. 92, No. 1, 2017, pp. 142-149.

[4]     Chen, C., Gao, M., and Zeng, X., Relationship Between Temperature at Cut Front Edge and Kerf Quality in Fiber Laser Cutting of Al–Cu Aluminum Alloy, International Journal of Machine Tools and Manufacture, Vol. 109, 2016, pp. 58-64.

[5]     Anicic, O., Jović, S., Skrijelj, H., and Nedić, B., Prediction of Laser Cutting Heat Affected Zone by Extreme Learning Machine, Optics and Lasers in Engineering, Vol. 88, 2017, pp. 1-4.

[6]     Adalarasan, R., Santhanakumar, M., and Rajmohan, M., Optimization of Laser Cutting Parameters for Al6061/SiCp/Al2O3 Composite Using Grey Based Response Surface Methodology (GRSM), Measurement, Vol. 73, 2015, pp. 596-606.

[7]     Long, N. P., Matsunaga, Y., Hanari, T., Yamada, T., and Muramatsu, T., Experimental Investigation of Transient Temperature Characteristic in High Power Fiber Laser Cutting of a Thick Steel Plate, Optics & Laser Technology, Vol. 84, 2016, pp. 134-43.

[8]     Petković, D., Nikolić, V., Milovančević, M., and Lazov, L., Estimation of the Most Influential Factors on the Laser Cutting Process Heat Affected Zone (HAZ) by Adaptive Neuro-Fuzzy Technique, Infrared Physics & Technology, Vol. 77, 2016, pp. 12-5.

[9]     Choubey, A., Jain, R. K., Ali, S., Singh, R., Vishwakarma, S. C., Agrawal, D. K., Arya, R., Kaul, R., Upadhyaya, B. N., and Oak, S. M., Studies on Pulsed Nd: YAG Laser Cutting of Thick Stainless Steel in Dry Air and Under Water Environment for Dismantling Applications, Optics & Laser Technology, Vol. 71, 2015, pp. 6-15.

[10]  Scintilla, L. D., Palumbo, G., Sorgente, D., and Tricarico, L., Fiber Laser Cutting of Ti6Al4V Sheets for Subsequent Welding Operations: Effect of Cutting Parameters on Butt Joints Mechanical Properties and Strain Behaviour, Materials & Design, Vol. 47, 2013, pp. 300-308.

[11]  Li, L., Sobih, M., and Crouse, P. L., Striation-Free Laser Cutting of Mild Steel Sheets, CIRP Annals-Manufacturing Technology, Vol. 56, No. 1, 2007, pp. 193-196.

[12]  Pocorni, J., Petring, D., Powell, J., Eckard, D. and Alexander, K., Measuring the Melt Flow on the Laser Cut Front, Nordic Laser Materials Processing Conference, Vol.15, 2015, pp. 25-27.

[13]  Pocorni, J., Petring, D., Powell, J., Deichsel, E. and Kaplan, A., The Effect of Laser Type and Power on the Efficiency of Industrial Cutting of Mild and Stainless Steels, Journal of Manufacturing Science and Engineering, Vol.138, 2015, pp. 1-6.

[14]  Ivarsona, A., Powell, J., and Siltanen, J., Influence of Alloying Elements on the Laser Cutting Process, Nordic Laser Materials Processing Conference, Vol. 15, 2015, pp. 84-88.

[15]  Vaziri, M., Soulati, A., and Bani Mostafa Arab, N., Effects of YAG Laser Cutting Parameters on Cut Quality of 316 Stainless Steel Sheets, J. Modares Mechanical Engineering, Vol. 15, No. 13, 2015, pp. 426-430.

[16]  Powell, J., Kaplan, A., A Comparison of Fiber Laser and CO₂ Laser Cutting, Macro Materials Processing, Vol. 69, 2013, pp. 23-27.

[17]  Powell, J., Kaplan, A., Mashikhi Al, S. O., and Voise, K. T. Y., Fibre Laser Cutting of Thin Section Mild Steel: An Explanation of the ‘Striation Free’ Effect”, Optics and Lasers in Engineering, Vol. 49, No. 8, 2011, pp. 1069–1075.

[18]  Yilbas, B. S., Karatas, C., Uslan, I., Keles, O., Usta, Y., Yilbas, Z., and Ahsan, M., Wedge Cutting of Mild Steel by CO₂ Laser and Cut-Quality Assessment in Relation to Normal Cutting, Optics and Lasers in Engineering, Vol. 46, No. 10, 2008, pp. 777-784.

[19]  Vladimir, A., Karasev, E., Influence of Basic Parameters of Metal Cutting with a Gas Laser on Process Energy Efficiency, XV International Symposium on Gas Flow, Vol. 5777, 2005, pp. 864-873.

[20]  Chen, K., Yao, Y. L., and Modi, V., Gas Dynamic Effects on Laser Cutting Quality, Journal of Manufacturing Processes, Vol. 3, No.1, 2001, pp. 38-49.

[21]  Ivarson, A., Powell, J., Kamalu, J., and Magnusson, C., The Oxidation Dynamics of Laser Cutting of Mild Steel and the Generation of Striations on the Cut Edge, Journal of Materials Processing Technology, Vol. 40, No. 3-4, 2000, pp. 359-374.

[22]  Hashemzadeh, M., Powell, J., and Voisey, K. T., Fibre Laser Piercing of Mild Steel–The Effects of Power Intensity, Gas type and Pressure, Optics and Lasers in Engineering, Vol. 55, 2014, pp. 143-149.