scholarly journals Cutting Properties of Austenitic Stainless Steel by Using Laser Cutting Process without Assist Gas

2012 ◽  
Vol 2012 ◽  
pp. 1-8
Author(s):  
Hitoshi Ozaki ◽  
Yosuke Koike ◽  
Hiroshi Kawakami ◽  
Jippei Suzuki

Recently, laser cutting is used in many industries. Generally, in laser cutting of metallic materials, suitable assist gas and its nozzle are needed to remove the molten metal. However, because of the gas nozzle should be set closer to the surface of a workpiece, existence of the nozzle seems to prevent laser cutting from being used flexible. Therefore, the new cutting process, Assist Gas Free laser cutting or AGF laser cutting, has been developed. In this process, the pressure at the bottom side of a workpiece is reduced by a vacuum pump, and the molten metal can be removed by the air flow caused by the pressure difference between both sides of the specimen. In this study, cutting properties of austenitic stainless steel by using AGF laser cutting with 2 kW CO2 laser were investigated. Laser power and cutting speed were varied in order to study the effect of these parameters on cutting properties. As a result, austenitic stainless steel could be cut with dross-free by AGF laser cutting. When laser power was 2.0 kW, cutting speed could be increased up to 100 mm/s, and kerf width at specimen surface was 0.28 mm.

2012 ◽  
Vol 706-709 ◽  
pp. 2228-2233
Author(s):  
Hitoshi Ozaki ◽  
Takahito Mima ◽  
Hiroshi Kawakami ◽  
Jippei Suzuki

Recently, laser cutting is used in many industries. Generally, in laser cutting of metallic materials, assist gas and its nozzle are needed to remove the molten metal. However, because of the gas nozzle should be moved closer to the position about 1 mm from the surface of a workpiece, it is thought that existence of the nozzle causes lack of flexibility of laser cutting. Therefore, the new cutting process, Assist Gas Free laser cutting (hereafter, called as AGF laser cutting), has been developed and investigated about cutting properties in our laboratory. In this process, the pressure at the bottom side of a workpiece is reduced by a vacuum pump, and the molten metal can be removed by the air flow caused by the pressure difference between both sides of the specimen. On the other hand, when cutting of metallic materials with a linear polarized laser is performed, it is known that the cutting kerf might slant. This phenomenon is also observed in AGF laser cutting. In the present study, cutting properties of austenitic stainless steel by using liner polarized CO2 laser in AGF laser cutting was investigated. Cutting speed and direction were varied in order to study the effect of these parameters on cutting properties. As a result, when the angle formed by the cutting direction and the polarized direction of laser was parallel, the kerf slant could be depressed, and the critical cutting speed could be the fastest in any other cutting direction.


Author(s):  
Asonganyi Ateh Atayo ◽  
Mahmood Bashir ◽  
Muhammad Mustafizur Rahman ◽  
Rajeev Nair

Abstract Stainless steel 304 is one of the most commonly used steel types for corrosion resistance applications, but higher melting point is a limitation in industries from a manufacturing point of view. The non-conventional and subtractive manufacturing technique of laser cutting — a beam directed method, is suitable for these applications. A Gaussian laser beam is directed at the material that melts, burns, vaporizes, or is blown away by a jet of gas, leaving a fine edge with good surface finish. In this study, a numerical study was performed to study the multi-physical fluid processes of laser cutting. Towards this, modeling was performed using 1.2 mm thick austenitic stainless-steel coupons that was cut using a continuous width neodymium-doped yttrium aluminum garnet (CW Nd: YAG) laser. The results showed smoother surface cut, little dross formation, lower temperature rise in heat affected zones, and less finish time at a cutting speed of 8m/min, higher laser power above 1000 W, gas pressure of 11 bars, and focus distance of −1.0 mm. It was observed that an increase in laser power at a faster cutting speed led to an increase in kerf width, reduction in dross formation, lower temperature rises in heat affected zones and a reduced finish time. The simulation results were compared with published experimental data and found to be well within a maximum difference of 15%.


2013 ◽  
Vol 664 ◽  
pp. 811-816 ◽  
Author(s):  
Imed Miraoui ◽  
Mohamed Boujelbene ◽  
Emin Bayraktar

Laser cutting of materials is becoming the preferred method of cutting. It has many advantages over conventional machining techniques such as better quality of cuts, quick and accurate cutting. The objective of this work is to investigate the effect of the main input laser cutting parameters, laser power and cutting speed, on the microhardness of stainless steel sheets obtained by CO2 laser cutting. The experimental tests were performed at various laser powers and cutting speeds. The cut surface was studied based on microhardness depth profiles beneath the machined surface. In order to investigate the metallurgical alterations beneath the cut surface, the microstructure was observed by using scanning electron microscopy. The results show that the microhardness and the surface microstructure are affected by laser cutting. Laser cutting leads to the formation of periodic striations and cracks. Also the main parameters of cutting, laser power and cutting speed, have an effect on surface microstructure and microhardness.


2022 ◽  
Vol 12 (1) ◽  
pp. 495
Author(s):  
Kwan Kim ◽  
Moo-Keun Song ◽  
Su-Jin Lee ◽  
Dongsig Shin ◽  
Jeong Suh ◽  
...  

With nuclear power plants worldwide approaching their design lifespans, plans for decommissioning nuclear power plants are increasing, and interest in decommissioning technology is growing. Laser cutting, which is suitable for high-speed cutting in underwater environments and is amenable to remote control and automation, has attracted considerable interest. In this study, the effects of laser cutting were analyzed with respect to relevant parameters to achieve high-quality underwater laser cutting for the decommissioning of nuclear power plants. The kerf width, drag line, and roughness of the specimens during the high-power laser cutting of 50 mm-thick stainless steel in an underwater environment were analyzed based on key parameters (focal position, laser power, and cutting speed) to determine the conditions for satisfactory cutting surface quality. The results indicated that underwater laser cutting with a speed of up to 130 mm/min was possible at a focal position of 30 mm and a laser power of 9 kW; however, the best-quality cutting surface was obtained at a cutting speed of 30 mm/min.


Author(s):  
Ioana Doyen ◽  
Christophe Chagnot ◽  
Christophe Journeau ◽  
Emmanuel Porcheron ◽  
Thomas Gelain ◽  
...  

Abstract Laser cutting, a contactless remote controlled process, was assessed for nuclear decommissioning applications, in full through-thickness-cutting (emerging cutting) and deep gouging (non-emerging) conditions. This work aims at presenting specific tools developed and implemented at CEA Saclay, to evaluate and to optimize new cutting strategies, in terms of robustness and reliability, in order to best adapt the laser cutting process to fuel debris retrieval specificities of Fukushima Daiichi reactors. Several configurations for deep gouging have been tested in DELIA facility to reach more than 40 mm of cut-thickness in one pass with an 8kW laser power. First, the laser cutting process was assessed on fused cast zirconia blocks and then on 316L stainless steel and fuel debris simulant blocks. This paper presents the main results of the tests performed in representative conditions of “in site conditions” such as: edge or bulk start/stop cutting, complex surface (i.e. surface with a varying topology) cutting, stand-off variation, angle of cut, trajectories misalignment, and material heterogeneity. Moreover, the excellent performances achieved on 316L stainless steel and fuel debris simulants indicate that deep gouging applied to nuclear decommissioning is a promising technology.


2010 ◽  
Vol 442 ◽  
pp. 81-87
Author(s):  
A. Rauf ◽  
A. Hussain ◽  
R. Akhter ◽  
W.A. Farooq ◽  
M. Aslam

Cutting of austenitic stainless steel of 0.5mm and 2mm thickness with CO2 laser has been carried out using oxygen, nitrogen and compressed air as assist gases. It has been observed that when oxygen is used as assist gas, the contribution of combustion energy was found to be 60 to 80 % more as compared to the other two types of assist gases. The cutting speed for 0.5 mm sheet was about 11 times where as for 2 mm stainless steel it was around 16 times. The role of combustion energy were theoretically calculated and compared with experimental results and found to be in good agreement.


2017 ◽  
Vol 20 (3) ◽  
pp. 101-107 ◽  
Author(s):  
V. Senthilkumar ◽  
G. Jayaprakash

Laser cutting is the popular unconventional manufacturing method widely used to cut various engineering materials. In this work CO2 laser cutting of AISI 314 satinless steel has been investigated. This paper focus on the investigation into the effect of laser cutting parameters like laser power, assist gas pressure, cutting speed and stand-off distance on surface roughness, hardness and kerf dimensions like kerf width, kerf ratio and kerf taper in CO2 laser cutting of AISI 314 stainless steel.


2015 ◽  
Vol 88 (1) ◽  
pp. 125-137 ◽  
Author(s):  
Shib Shankar Banerjee ◽  
Anil K. Bhowmick

ABSTRACT The application of the low-power CO2 laser-cutting process to fluoroelastomer (FKM), polyamide 6 (PA6), PA6/FKM thermoplastic elastomers (TPEs), and their thermoplastic vulcanizate (TPV) is reported. The main laser process parameters studied were laser power, cutting speed, and material thickness. The value of the top and bottom widths of the slit that were formed during laser cutting (kerf width), melted transverse area, and melted volume per unit time were measured and analyzed. Interestingly, TPE showed a smaller melted area and melted volume per unit time when compared with those values with PA6. Dynamic vulcanization further decreased these values. For example, the melted areas of PA6 and TPE were 510 × 10−3 mm2 and 305 × 10−3 mm2, respectively, which reduced to 238 × 10−3 mm2 for TPV at 40 W laser power. FKM showed the lowest value (melted area of 180 × 10−3 mm2). In addition, the output quality of the cut surface was examined by measuring the root mean square (RMS) roughness of the cut edges and heat-affected zone (HAZ). The obtained results indicated that the dimension of the HAZ and RMS roughness largely decreased in TPE when compared with PA6. For example, the HAZ of PA6 was 700 μm, which decreased to 230 μm for TPE at 40 W laser power. On the other hand, HAZ was nonexistent for FKM. Infrared spectroscopic analysis showed that there was no structural change of TPE or pristine polymers after applying the low-power CO2 laser on the surface of materials. CO2 laser cutting will be a new technique in this industry, and this analysis will assist the manufacturing industry to choose a suitable laser system with exhaustive information of process parameters for cutting or machining of rubber, TPEs, and TPVs.


2018 ◽  
Vol 103 ◽  
pp. 311-317 ◽  
Author(s):  
Sangwoo Seon ◽  
Jae Sung Shin ◽  
Seong Yong Oh ◽  
Hyunmin Park ◽  
Chin-Man Chung ◽  
...  

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