Proceedings of SerbiaTrib '13

Serbian TribologySocietySERBIATRIB ‘1313 th International Conference onTribologyKragujevac, Serbia, 15 – 17 May 2013Faculty of Engineeringin KragujevacQUALITY OF PLASMA CUTTINGBogdan Nedić 1 , Marko Janković 2 , Miroslav Radovanović 3 , Gordana Globočki Lakić 41University of Kragujevac, Faculty of engineering, Kragujevac, nedic@kg.ac.rs2Fiat automobili Srbija, Kragujevac3University of Niš, Faculty of mechanical engineering, Niš4 Univerzitet u Banja Luci, Mašinski fakultet, Banja Luka, RS, BiHAbstract: The plasma arc cutting process severs metal by using a constricted arc to melt a localized area ofa workpiece, removing the molten material with a high-velocity jet of ionized gas issuing from theconstricting orifice. The ionized gas is a plasma, hence the name of the process. This paper analyzes qualityof cut in plasma arc cutting. Quality of cut in plasma arc cutting is defined using standard EN ISO 9013. Thecorrelation between quality of plasma cut Conclusions of other authors who investigated quality of plasmacut are also presented.In the second part of the paper, experimental investigation of plasma cut waspresented. Samples of steel plate thickness of 15 mm were used for creating 17 cuts. Obtained experimentalresults are consistent with theoretical considerations, as well as previous experimental results.Keywords: Plasma arc cutting, experiment, quality of cut, process parameters1. INTRODUCTIONThe efficient manufacture of high-quality platecomponents is quite difficult task. One of theeasiest methods of contour cutting steel is oxy-fuelcutting. With respect to oxy-fuel cutting, lasercutting, abrasive water jet cutting, and plasmacutting are new attractive advanced processes forcontour cutting of plate. They have numerousadvantages, namely, a narrow cut, a proper cutprofile, smooth and flat edges, minimaldeformation of a workpiece, the possibility ofapplying high feed rates, intricate profilemanufacture and fast adaptation to changes inmanufacturing programs [1].Plasma cutting is an industrial process that isessentially controlled by the operator who usesrecommendations given by the manufacturers of thecutting equipment. Those recommendations,however, reflect the point of view of themanufacturers’ business, which includes not onlyselling the cutting torches but also the consumables.Yet, the manufacturers’ recommendations usuallylead to solutions that are technically sound in termsof cutting quality, but do not necessarily correspondto the most cost-effective solutions on the user’spoint of view [2].As a result, the user attempts to optimize thecutting operations by trial-and-error every time it isneeded to setup the existing equipment for a newdifferent task.This requires the development of full studies andapply theoretical and experimental researchesamong all the technological system’s links, in order toestablish (chose) the optimal processing variant.2. PROCESS PARAMETERSAs in the case of other machining methods, atthe plasma arc cutting (PAC), in order to obtaingood results, it is very important to well know theprocess, this meaning to exactly know what are theparameters involved in the process and theirinfluences (fig. 1).Input parameters are those parameters that canbe controlled, and their values are known and canbe set by the operator. Output parameters related tothe quality of the obtained surface. Factors whichcannot be controlled coming from machines andwork environment.314 13 th International Conference on Tribology – Serbiatrib’13