Purpose of this study is to determine the most advantageous cutting method for a better competition chance. By presenting high hardness, high strength and superior toughness Hardox 500 steel. This sample was cut by plasma, laser, wire erosion and abrasive water jet (AWJ) methods from advanced cutting technologies. By taking micro structure photos of surface of the sample cut by different cutting methods, effects of different cutting methods on metallurgical structure of material were compared

A. Karabulut

İ. Dahil

L. Dahil

English

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291 METALURGIJA 53 (2014) 3, 291-294L. DAHIL, İ. DAHILCOMPARISON OF ADVANCED CUTTING TECHNIQUES ON HARDOX 500 STEEL MATERIAL AND THE EFFECT OF STRUCTURAL PROPERTIES OF THE MATERIALReceived – Prispjelo: 2013-01-24Accepted – Prihvaćeno: 2013-10-28Original Scientific Paper – Izvorni znanstveni radISSN 0543-5846METABK 53(3) 291-294(2014)UDC – UDK 669.15:621.96:620.18:620.178.1=111L. Dahil, Istanbul A ydın University , Department of Mechanical and Metal Technologies, Turkey. A. Karabulut, Afyon Kocatepe University, Faculty of Technology, Mechanical Engineering, Turkeyİ. Dahil, Ministry of Education, Istanbul Provincial Administration of Education, TurkeyPurpose of this study is to determine the most advantageous cutting method for a better competition chance. By presenting high hardness, high strength and superior toughness Hardox 500 steel. This sample was cut by plasma, laser, wire erosion and abrasive water jet (AWJ) methods from advanced cutting technologies. By taking micro struc-ture photos of surface of the sample cut by different cutting methods, effects of different cutting methods on metal-lurgical structure of material were compared.Key words: Hardox 500, advanced cutting techniques, micro structure, hardnessINTRODUCTIONConventional methods have different disadvantages that could cause decrease of importance shown to them in market. In recent years, there are manufacturing methods called as developed advanced cutting tech-niques. These manufacturing methods are wire erosion, laser, plasma and abrasive water jet. In the environment where national and international competition have been increasing every passing day, it has become more and more important to make proper selection required mini-mum process.In the optimization study made for the selection of processing parameters of wire erosion, important factors affecting processing performance were determined by using Taguchi experiment design method and analysis of variance [1]. Processing with wire erosion allows mould members to be processed in high-measurement precision, after being exposed to heat treatment, because hard mate-rials, which are manufactured very difficult according to classic processing methods, could be processed provided that being conductive [2]. In wire erosion, generally, a hard layer and hair cracks occur on the surface of work piece depending on performed processing conditions and thermal features of material [3]. With wire erosion, chip is removed from work piece through electro thermal en-ergy, for this reason, machining ratio depends on electri-cal conductivity and heat of melting of work piece [4]. Gas parameters, power supply parameters and cutting speed are important parameters for plasma cut [5]. Sur-face roughness is defined by fluctuation on the surface and size of the fluctuation is proportional to diameter of jet [6]. When rate of feed of jet is decreased, it was deter-mined that abrasive particles lose partially their accura-cies in the deformation abrasion zone and the particles separating from the cutting material increase hole depths by touching the surface [7]. Water jet has been becoming more and more effective than the other methods compet-ing with it, because it has no thermal effect especially on cutting material [8]. An surface roughness that increases depending on cutting depth is inevitable likewise laser cutting, plasma, underwater plasma and oxygen flame [9]. Due to cutting process with water jet is provided by water, it is totally proper to health conditions needed in food sector [10]. Water jet is a cutting tool, which is non-abrasive, with non-apparent turning, don’t leave burrs at corners, generates powers that will deform the material during cutting, without temperature influence and there-fore occurrence of structural defect, tarnish, distortion, melting, dropping and burning problems don’t come into question, can cut even the most complicated shapes by its high sensibility and very clean surface properties [11]. While laser cutting and plasma cut, structural alterations, which possessed high hardness degree and processed with difficulty, occur on cutting surfaces because of the used thermal energy [12].In this study, examination of hardness and micro structure changes, which occur on the surface of shear of cutting sample and on backwards areas from cutting surface because of the non-conventional different cut-ting methods, and determination of the most advanta-geous cutting method, were proposed.MATERIALS AND METHODSIn experimental studies done, Hardox 500 steel sam-ple, which is commonly used in heavy industry and 292   METALURGIJA 53 (2014) 3, 291-294L. DAHIL et al.: COMPARISON OF ADVANCED CUTTING TECHNIQUES ON HARDOX 500 STEEL MATERIAL...manufacturing and many phases about manufacture and keep high hardness, high strength and superior tough-ness together, was used. Size of sample is been 20x20x15 mm. Prepared sample was cut by plasma, laser, wire erosion and abrasive water jet (AWJ) methods of ad-vanced cutting technologies.By comparing micro structure photos of the sample cut by different cutting methods with micro structure photos of the original sample, effects of different cut-ting methods on metallurgical structure of the material were evaluated. In addition, on the sample cut by differ-ent methods, effects of hardness variation were exam-ined on the graphics obtained by making hardness measurements from cutting edge towards the core. Plasma cuttingCutting method for CNC plasma machines is the thermal processing method that takes the electric energy from power supply and transmits it to the material to be processed, under the guidance of torc and protection of substitute gases, and during this process, that uses an ionized and electric transmitter gas as transfer media [13]. State of the sample cut by plasma, is shown on Figure 1.Laser cuttingLaser cutting method can be defined as transmission of photon energy to the material to be processed by thermal or photochemical ways, “atom-atom” process-ing of the material to be processed by melting or evapo-ration and revulsion of melted material by the help of using gases.State of the sample cut by plasma, is shown on Fig-ure 2.Wire erosion cuttingWire erosion is the method of cutting with the help of a wire on which high-density flow is passed. On these looms, when wire electrode connected to different elec-trical poles is approximated to work piece, a high tem-perature occurs with high discharges and chip is re-moved by local metal defrosting way [14]. State of the sample cut by plasma, is shown on Figure 3.Cutting by abrasive water jetCutting technology by Water Jet is based upon that obtained beam of water jet at high speeds by crossing the pressure increased water (4000 bar) through a nar-row range discharges particles from the material by im-pact effect, and as a result of this, processing of the ma-terial. It is a method that can cut all kinds of materials with thickness from 0,1 mm to 200 mm [15].While cutting the materials by abrasive water jet, QMAX Abrasive Water Jet was used. Among GMA Garnet, Garnet and Power Garnet, abrasives which are commonly used, GMA Garnet was used in this study. State of the sample cut by abrasive water jet, is shown on Figure 4.Hardness of the cut surfaces was measured by “HV0.5” value in “SHUMAZU” hardness measuring instrument. Photos of cut surfaces were taken by zoom-ing their micro structures 500 times by the help of “OL-YMPUS BX-60 Model” microscope and TV tuner and software on “Inter Core 2 Duo PC”.In order to examine variable hardness values of ma-terials cut by different cutting methods and structural defect and alterations in microstructures and on surface caused by cutting method, edges neighboring on sur-face of shear of cut samples were cleaned by 240 - 1 200 papers consisting of SiC granules in different granule sizes and placed on rotating disk. The reason why clean-ing and polishing operations are applied on borders neighboring on surface of shear is to examine hardness alteration from the border of surface of shear to inward. The process was carried out until the base is parallel to the surface on which examinations will be made. For polishing process, aluminum powder and dia-mond paste were used as abrasive. After providing the gloss completely, the surface to be seared and examined was cleaned by washing with water and alcohol.  These operations were carried out until the desired surface is obtained for metallurgical examinations. Each polished material was seared by 3 % nital for 6 seconds in order to find out surface structures. After searing op-eration, the surface to be examined was cleaned by Figure 1   Photo of surface of shear of the sample cut by plasma Figure 2   Photo of surface of shear of the sample cut by laserFigure 3   Photo of surface of shear of the sample cut by wire erosionFigure 4   Photo of surface of shear of the sample cut by abrasive water jet293 METALURGIJA 53 (2014) 3, 291-294L. DAHIL et al.: COMPARISON OF ADVANCED CUTTING TECHNIQUES ON HARDOX 500 STEEL MATERIAL...washing pure water and alcohol. Seared materials were zoomed 500 times by examining under optical micro-scope and then their micro structure photos were taken. The micro structure is at a point, which is non-af-fected by cutting method, and the structure is formed at cutting edge were examined comparatively in order to observe alterations in micro structures of material. In order to find differences resulted in examination, a large number of photos were taken three different points from material surface and deformation in the structure of material caused by cutting method and hardness changes were determined as a result of exam-ining all of these photos. Hardness measurements of materials, which their micro structures were examined, were carried out by Vickers hardness measuring device and the obtained re-sults were transmitted on graphics. On the same sample, by measuring hardness at intervals of two each millim-eters from cutting border to core, hardness changes were determined from cutting border towards core and effects of different methods were evaluated depending on these alterations.DISCUSSIONDuring different cutting operations applied on pre-pared sample, it was observed that temperature changes would cause what kind of changes on external structure of piece and then the results were compared with micro measurements. Neighboring surfaces of surfaces ob-tained as a result of cutting were subjected to micro structural examination by polishing. After micro film and hardness measurement opera-tions, hardness and structural changes that occur de-pending on cutting methods on material, were evaluat-ed. On figure 5(a), 5(b), 5(c), 5(d) and 5(e) illustrate micro structure photos of cutting border and surfaces of the sample cut by different cutting methods. Cut surface with different methods of hardness chan-ges % resulted in these comparisons are illustrated on Table 1. As seen on Table 1, there isn’t a significant change on surface, micro structure and cutting edge of the material, only in cutting by water jet among these cutting methods. In order to determine these changes coming into ex-istence on these cut materials, original hardness value of the sample that was not subjected to cutting operation was determined primarily. In order to carry out determi-nation and comparison of the changes after cutting op-erations, hardness values in Vickers (HV) were meas-ured at 2, 4, 6 mm distances on neighboring surface from cutting edges towards centre. Graphic, which have been formed to figure out what kind of a change is pre-sented towards inside of material by hardness values on the cut surfaces of the sample subjected to different cut-ting methods and to make comparison to before and af-ter the operation, are given on figure 6.When these graphics are examined, it is seen that hardness values change depending on microstructure of material in different cutting methods. It is clearly no-ticed that cutting method with maximum change is plas-ma cutting and cutting method with minimum change is abrasive water jet cutting.By seeing different hardness values of different ma-terials, it has been seen that water jet cutting provides superior advantage and completes the operation without causing any internal strain for materials. As for the oth-er cutting methods, wire erosion, laser and plasma cut-tings follow grading of water jet in terms of advantage. a) Before cutting  b) Cut by water jet  c) Cut by plasma  d) Cut by laser cutting  e) Cut by wire erosionFigure 5 Micro structure photos of cutting border and surfaces of the sample cut by different cutting methodsTable 1   Depending on the original hardness of the material cut, the cut surface with different methods of hardness changeCutting Method Hardox 500Hardness / HV Change / %Core 600 -Water Jet 602 0,33Wire Eroison 638 6,34Laser 655 9,16Plasma 672 12,10Figure 6 HV 0.5 Hardness measurement graphics294   METALURGIJA 53 (2014) 3, 291-294L. DAHIL et al.: COMPARISON OF ADVANCED CUTTING TECHNIQUES ON HARDOX 500 STEEL MATERIAL...CONCLUSIONSOn the surfaces cut by method of abrasive water jet, because any thermal treatment didn’t occur on the field touched by jet beam, material didn’t have any micro-structure change and hardness differences depending on cutting. When effects of different cutting methods on metal-lurgical properties of cut surface are taken into consid-eration, it is seen that method of AWJ cutting, which gives the most positive results, comes into prominence. While different temperature and cooling effects that exist during advanced cutting methods have an impor-tant impacts on metallurgical properties of the exam-ined materials, a zone affected by temperature doesn’t occur on cut surfaces and there won’t be a defect in original structure of the material, because temperature is not too high in AWJ cutting. This situation means that there cannot be a change for mechanic properties de-pending on the metallurgical properties. Among four different method examined in conse-quence of experiment, if an evaluation is made by tak-ing into consideration micro structural changes of the zone affected by temperature, it is seen that the most negative method is “ Plasma cut” and the most positive method is “AWJ cutting”. Methods in which advanced cutting methods are ap-plied, mechanic properties of the material also change depending on the effect of material on metallurgical ef-fects after cutting. In consequence of experimental stud-ies conducted, this situation is verified because hard-ness values measured on the surfaces cut by different methods are more different than original values of the materials. Since all the applied cutting methods apart from wa-ter jet contain heat treatment, they cause a significant change for hardness of material. Hardness changes are been different depending on the properties of cutting methods. This difference changes depending on heat and temperature formed during cutting and cooling con-ditions.REFERENCES[1]   Y. S. Liao, J. T. Huang, H. C. Su, A study on the machining parameter optimization of wire electrical discharge machi-ning. Journal of Materials Processing Technology, 71 (1997), 487-493.[2]   C. Özek, C, Cebeli, Investigation on the Interruption of gear steel in wire EDM Ç8620. Dokuz Eylul University Faculty of Engineering Science and Engineering Journal, 5 (2003), 47-52.[3]   K.Y, Chou, C. J. Evans, White layer sand thermal mode-ling of hard turned surfaces. International  Journal of Ma-chine Tools and Manufacture, 39 (1999) 1863-1881.[4]   M. Ay, D. Aydoğdu, Experimental investigation of the ef-fects of particle size measurement of wire EDM cutting parameters. Electronic Journal of Machine Technologies, (2010), 31-44.[5]   A. E. Kutlu, M. Monno, R. Bini, An overview of the me-thod of plasma cutting. Journal Engineers and Machinery, 46 (2005), 21-29.[6]   A. Akkurt, Effect of cutting speed on surface roughness in AWJ cutting applications of comercial püre aluminium and Al-6061 Aluminium alloy. Journal of Polytechnic, 8 (2005), 69-79.[7]   H. Blickwedel, N. S. Guo, H. Haferkamp, H. Louis, Pre-diction of abrasive jet cutting performance and quality. Proceedings of 9th International Symposium On Jet Cut-ting Technology (1990), 163-179 Cranfield: UK. [8]   A. Akkurt, Comparision of cut surface properties obtained from AISI 1030 steel by abresive water jet and by other methodologies. Pamukkale University Journal of Enginee-ring Sciences, 15 (2009), 142-152.[9]   N. S. Guo, H. Louis, H. G. Meier, Recycling capability of abrasive water jet cutting. Fluid Mechanics and Its Appli-cations. 13 (1992), 503-523. [10]   T. J. Steinhauser, Abrasive water jets on the cutting edge of technology. Flow Systems. USA. 1989[11]   C.Ojmertz, Abrasive water jet machining chalmers teknıska hogskola. Chalmers Unıversıty of Technology Goteborg Sweden, (1994), 91-96.[12]  M. Hashish, Optimization factors in abrasive water jet ma-chining. Journal of Engineering for Industry, 113 (1991), 132-139.[13]   Y. H. Çelik, C. Özek, CNC plasma cutting quality and cut-ting investigate the effect of processing parameters. 6th International Advanced Technologies Symposium. Elazığ: Turkey; 2011[14]   R. E. Willams, K. P. Rajukar, E. Bağcı, Study of wire elec-trical discharge machined surface characteristics. Journal of Materials Processing Technology, 28 (1991), 127-138. [15]   N. Geren, T. Tunç, The use of abrasive water-jet cutting systems in the metal industry and the cutting characteristi-cs. Journal of Engineers and Machine. 42 (2001), 42-49.Note:   The responsible translator for English language: Gülsen Bozde-mir, Ankara, Turkey

Comparison of advanced cutting techniques on hardox 500 steel material and the effect of structural properties of the material

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291METALURGIJA 53 (2014) 3, 291-294L. DAHIL, İ. DAHILCOMPARISON OF ADVANCED CUTTING TECHNIQUES ON HARDOX 500 STEEL MATERIAL AND THE EFFECT OF STRUCTURAL PROPERTIES OF THE MATERIALReceived – Prispjelo: 2013-01-24Accepted – Prihvaćeno: 2013-10-28Original Scientific Paper – Izvorni znanstveni radISSN 0543-5846METABK 53(3) 291-294(2014)UDC – UDK 669.15:621.96:620.18:620.178.1=111L. Dahil, Istanbul Aydın University, Department of Mechanical and Metal Technologies, Turkey. A. Karabulut, Afyon Kocatepe University, Faculty of Technology, Mechanical Engineering, Turkeyİ. Dahil, Ministry of Education, Istanbul Provincial Administration of Education, TurkeyPurpose of this study is to determine the most advantageous cutting method for a better competition chance. By presenting high hardness, high strength and superior toughness Hardox 500 steel. This sample was cut by plasma, laser, wire erosion and abrasive water jet (AWJ) methods from advanced cutting technologies. By taking micro struc-ture photos of surface of the sample cut by different cutting methods, effects of different cutting methods on metal-lurgical structure of material were compared.Key words: Hardox 500, advanced cutting techniques, micro structure, hardnessINTRODUCTIONConventional methods have different disadvantages that could cause decrease of importance shown to them in market. In recent years, there are manufacturing methods called as developed advanced cutting tech-niques. These manufacturing methods are wire erosion, laser, plasma and abrasive water jet. In the environment where national and international competition have been increasing every passing day, it has become more and more important to make proper selection required mini-mum process.In the optimization study made for the selection of processing parameters of wire erosion, important factors affecting processing performance were determined by using Taguchi experiment design method and analysis of variance [1]. Processing with wire erosion allows mould members to be processed in high-measurement precision, after being exposed to heat treatment, because hard mate-rials, which are manufactured very difficult according to classic processing methods, could be processed provided that being conductive [2]. In wire erosion, generally, a hard layer and hair cracks occur on the surface of work piece depending on performed processing conditions and thermal features of material [3]. With wire erosion, chip is removed from work piece through electro thermal en-ergy, for this reason, machining ratio depends on electri-cal conductivity and heat of melting of work piece [4]. Gas parameters, power supply parameters and cutting speed are important parameters for plasma cut [5]. Sur-face roughness is defined by fluctuation on the surface and size of the fluctuation is proportional to diameter of jet [6]. When rate of feed of jet is decreased, it was deter-mined that abrasive particles lose partially their accura-cies in the deformation abrasion zone and the particles separating from the cutting material increase hole depths by touching the surface [7]. Water jet has been becoming more and more effective than the other methods compet-ing with it, because it has no thermal effect especially on cutting material [8]. An surface roughness that increases depending on cutting depth is inevitable likewise laser cutting, plasma, underwater plasma and oxygen flame [9]. Due to cutting process with water jet is provided by water, it is totally proper to health conditions needed in food sector [10]. Water jet is a cutting tool, which is non-abrasive, with non-apparent turning, don’t leave burrs at corners, generates powers that will deform the material during cutting, without temperature influence and there-fore occurrence of structural defect, tarnish, distortion, melting, dropping and burning problems don’t come into question, can cut even the most complicated shapes by its high sensibility and very clean surface properties [11]. While laser cutting and plasma cut, structural alterations, which possessed high hardness degree and processed with difficulty, occur on cutting surfaces because of the used thermal energy [12].In this study, examination of hardness and micro structure changes, which occur on the surface of shear of cutting sample and on backwards areas from cutting surface because of the non-conventional different cut-ting methods, and determination of the most advanta-geous cutting method, were proposed.MATERIALS AND METHODSIn experimental studies done, Hardox 500 steel sam-ple, which is commonly used in heavy industry and 292  METALURGIJA 53 (2014) 3, 291-294L. DAHIL et al.: COMPARISON OF ADVANCED CUTTING TECHNIQUES ON HARDOX 500 STEEL MATERIAL...manufacturing and many phases about manufacture and keep high hardness, high strength and superior tough-ness together, was used. Size of sample is been 20x20x15 mm. Prepared sample was cut by plasma, laser, wire erosion and abrasive water jet (AWJ) methods of ad-vanced cutting technologies.By comparing micro structure photos of the sample cut by different cutting methods with micro structure photos of the original sample, effects of different cut-ting methods on metallurgical structure of the material were evaluated. In addition, on the sample cut by differ-ent methods, effects of hardness variation were exam-ined on the graphics obtained by making hardness measurements from cutting edge towards the core. Plasma cuttingCutting method for CNC plasma machines is the thermal processing method that takes the electric energy from power supply and transmits it to the material to be processed, under the guidance of torc and protection of substitute gases, and during this process, that uses an ionized and electric transmitter gas as transfer media [13]. State of the sample cut by plasma, is shown on Figure 1.Laser cuttingLaser cutting method can be defined as transmission of photon energy to the material to be processed by thermal or photochemical ways, “atom-atom” process-ing of the material to be processed by melting or evapo-ration and revulsion of melted material by the help of using gases.State of the sample cut by plasma, is shown on Fig-ure 2.Wire erosion cuttingWire erosion is the method of cutting with the help of a wire on which high-density flow is passed. On these looms, when wire electrode connected to different elec-trical poles is approximated to work piece, a high tem-perature occurs with high discharges and chip is re-moved by local metal defrosting way [14]. State of the sample cut by plasma, is shown on Figure 3.Cutting by abrasive water jetCutting technology by Water Jet is based upon that obtained beam of water jet at high speeds by crossing the pressure increased water (4000 bar) through a nar-row range discharges particles from the material by im-pact effect, and as a result of this, processing of the ma-terial. It is a method that can cut all kinds of materials with thickness from 0,1 mm to 200 mm [15].While cutting the materials by abrasive water jet, QMAX Abrasive Water Jet was used. Among GMA Garnet, Garnet and Power Garnet, abrasives which are commonly used, GMA Garnet was used in this study. State of the sample cut by abrasive water jet, is shown on Figure 4.Hardness of the cut surfaces was measured by “HV0.5” value in “SHUMAZU” hardness measuring instrument. Photos of cut surfaces were taken by zoom-ing their micro structures 500 times by the help of “OL-YMPUS BX-60 Model” microscope and TV tuner and software on “Inter Core 2 Duo PC”.In order to examine variable hardness values of ma-terials cut by different cutting methods and structural defect and alterations in microstructures and on surface caused by cutting method, edges neighboring on sur-face of shear of cut samples were cleaned by 240 - 1 200 papers consisting of SiC granules in different granule sizes and placed on rotating disk. The reason why clean-ing and polishing operations are applied on borders neighboring on surface of shear is to examine hardness alteration from the border of surface of shear to inward. The process was carried out until the base is parallel to the surface on which examinations will be made. For polishing process, aluminum powder and dia-mond paste were used as abrasive. After providing the gloss completely, the surface to be seared and examined was cleaned by washing with water and alcohol.  These operations were carried out until the desired surface is obtained for metallurgical examinations. Each polished material was seared by 3 % nital for 6 seconds in order to find out surface structures. After searing op-eration, the surface to be examined was cleaned by Figure 1  Photo of surface of shear of the sample cut by plasma Figure 2  Photo of surface of shear of the sample cut by laserFigure 3  Photo of surface of shear of the sample cut by wire erosionFigure 4  Photo of surface of shear of the sample cut by abrasive water jet293METALURGIJA 53 (2014) 3, 291-294L. DAHIL et al.: COMPARISON OF ADVANCED CUTTING TECHNIQUES ON HARDOX 500 STEEL MATERIAL...washing pure water and alcohol. Seared materials were zoomed 500 times by examining under optical micro-scope and then their micro structure photos were taken. The micro structure is at a point, which is non-af-fected by cutting method, and the structure is formed at cutting edge were examined comparatively in order to observe alterations in micro structures of material. In order to find differences resulted in examination, a large number of photos were taken three different points from material surface and deformation in the structure of material caused by cutting method and hardness changes were determined as a result of exam-ining all of these photos. Hardness measurements of materials, which their micro structures were examined, were carried out by Vickers hardness measuring device and the obtained re-sults were transmitted on graphics. On the same sample, by measuring hardness at intervals of two each millim-eters from cutting border to core, hardness changes were determined from cutting border towards core and effects of different methods were evaluated depending on these alterations.DISCUSSIONDuring different cutting operations applied on pre-pared sample, it was observed that temperature changes would cause what kind of changes on external structure of piece and then the results were compared with micro measurements. Neighboring surfaces of surfaces ob-tained as a result of cutting were subjected to micro structural examination by polishing. After micro film and hardness measurement opera-tions, hardness and structural changes that occur de-pending on cutting methods on material, were evaluat-ed. On figure 5(a), 5(b), 5(c), 5(d) and 5(e) illustrate micro structure photos of cutting border and surfaces of the sample cut by different cutting methods. Cut surface with different methods of hardness chan-ges % resulted in these comparisons are illustrated on Table 1. As seen on Table 1, there isn’t a significant change on surface, micro structure and cutting edge of the material, only in cutting by water jet among these cutting methods. In order to determine these changes coming into ex-istence on these cut materials, original hardness value of the sample that was not subjected to cutting operation was determined primarily. In order to carry out determi-nation and comparison of the changes after cutting op-erations, hardness values in Vickers (HV) were meas-ured at 2, 4, 6 mm distances on neighboring surface from cutting edges towards centre. Graphic, which have been formed to figure out what kind of a change is pre-sented towards inside of material by hardness values on the cut surfaces of the sample subjected to different cut-ting methods and to make comparison to before and af-ter the operation, are given on figure 6.When these graphics are examined, it is seen that hardness values change depending on microstructure of material in different cutting methods. It is clearly no-ticed that cutting method with maximum change is plas-ma cutting and cutting method with minimum change is abrasive water jet cutting.By seeing different hardness values of different ma-terials, it has been seen that water jet cutting provides superior advantage and completes the operation without causing any internal strain for materials. As for the oth-er cutting methods, wire erosion, laser and plasma cut-tings follow grading of water jet in terms of advantage. a) Before cutting b) Cut by water jet c) Cut by plasma d) Cut by laser cutting e) Cut by wire erosionFigure 5 Micro structure photos of cutting border and surfaces of the sample cut by different cutting methodsTable 1  Depending on the original hardness of the material cut, the cut surface with different methods of hardness changeCutting Method Hardox 500Hardness / HV Change / %Core 600 -Water Jet 602 0,33Wire Eroison 638 6,34Laser 655 9,16Plasma 672 12,10Figure 6 HV 0.5 Hardness measurement graphics294  METALURGIJA 53 (2014) 3, 291-294L. DAHIL et al.: COMPARISON OF ADVANCED CUTTING TECHNIQUES ON HARDOX 500 STEEL MATERIAL...CONCLUSIONSOn the surfaces cut by method of abrasive water jet, because any thermal treatment didn’t occur on the field touched by jet beam, material didn’t have any micro-structure change and hardness differences depending on cutting. When effects of different cutting methods on metal-lurgical properties of cut surface are taken into consid-eration, it is seen that method of AWJ cutting, which gives the most positive results, comes into prominence. While different temperature and cooling effects that exist during advanced cutting methods have an impor-tant impacts on metallurgical properties of the exam-ined materials, a zone affected by temperature doesn’t occur on cut surfaces and there won’t be a defect in original structure of the material, because temperature is not too high in AWJ cutting. This situation means that there cannot be a change for mechanic properties de-pending on the metallurgical properties. Among four different method examined in conse-quence of experiment, if an evaluation is made by tak-ing into consideration micro structural changes of the zone affected by temperature, it is seen that the most negative method is “ Plasma cut” and the most positive method is “AWJ cutting”. Methods in which advanced cutting methods are ap-plied, mechanic properties of the material also change depending on the effect of material on metallurgical ef-fects after cutting. In consequence of experimental stud-ies conducted, this situation is verified because hard-ness values measured on the surfaces cut by different methods are more different than original values of the materials. Since all the applied cutting methods apart from wa-ter jet contain heat treatment, they cause a significant change for hardness of material. Hardness changes are been different depending on the properties of cutting methods. This difference changes depending on heat and temperature formed during cutting and cooling con-ditions.REFERENCES[1]  Y. S. Liao, J. T. Huang, H. C. Su, A study on the machining parameter optimization of wire electrical discharge machi-ning. Journal of Materials Processing Technology, 71 (1997), 487-493.[2]  C. Özek, C, Cebeli, Investigation on the Interruption of gear steel in wire EDM Ç8620. Dokuz Eylul University Faculty of Engineering Science and Engineering Journal, 5 (2003), 47-52.[3]  K.Y, Chou, C. J. Evans, White layer sand thermal mode-ling of hard turned surfaces. International  Journal of Ma-chine Tools and Manufacture, 39 (1999) 1863-1881.[4]  M. Ay, D. Aydoğdu, Experimental investigation of the ef-fects of particle size measurement of wire EDM cutting parameters. Electronic Journal of Machine Technologies, (2010), 31-44.[5]  A. E. Kutlu, M. Monno, R. Bini, An overview of the me-thod of plasma cutting. Journal Engineers and Machinery, 46 (2005), 21-29.[6]  A. Akkurt, Effect of cutting speed on surface roughness in AWJ cutting applications of comercial püre aluminium and Al-6061 Aluminium alloy. Journal of Polytechnic, 8 (2005), 69-79.[7]  H. Blickwedel, N. S. Guo, H. Haferkamp, H. Louis, Pre-diction of abrasive jet cutting performance and quality. Proceedings of 9th International Symposium On Jet Cut-ting Technology (1990), 163-179 Cranfield: UK. [8]  A. Akkurt, Comparision of cut surface properties obtained from AISI 1030 steel by abresive water jet and by other methodologies. Pamukkale University Journal of Enginee-ring Sciences, 15 (2009), 142-152.[9]  N. S. Guo, H. Louis, H. G. Meier, Recycling capability of abrasive water jet cutting. Fluid Mechanics and Its Appli-cations. 13 (1992), 503-523. [10]  T. J. Steinhauser, Abrasive water jets on the cutting edge of technology. Flow Systems. USA. 1989[11]  C.Ojmertz, Abrasive water jet machining chalmers teknıska hogskola. Chalmers Unıversıty of Technology Goteborg Sweden, (1994), 91-96.[12] M. Hashish, Optimization factors in abrasive water jet ma-chining. Journal of Engineering for Industry, 113 (1991), 132-139.[13]  Y. H. Çelik, C. Özek, CNC plasma cutting quality and cut-ting investigate the effect of processing parameters. 6th International Advanced Technologies Symposium. Elazığ: Turkey; 2011[14]  R. E. Willams, K. P. Rajukar, E. Bağcı, Study of wire elec-trical discharge machined surface characteristics. Journal of Materials Processing Technology, 28 (1991), 127-138. [15]  N. Geren, T. Tunç, The use of abrasive water-jet cutting systems in the metal industry and the cutting characteristi-cs. Journal of Engineers and Machine. 42 (2001), 42-49.Note:  The responsible translator for English language: Gülsen Bozde-mir, Ankara, Turkey

Comparison of advanced cutting techniques on hardox 500 steel material and the effect of structural properties of the material

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