Influence of plasma torch design on cutting quality during precision air-plasma cutting of metal

Optical interferometry and metallographic analysis were used to study the structure of cutting seams obtained after 09G2S steel cutting by a PMVR-5 plasma torch. These plasma torches have many design features in the gas-dynamic stabilization system of the plasma arc. The application of a new plasma torch can obtain higher quality and lower energy costs of cutting medium-thick 09G2S steel. Metallographic analysis has shown that the qualitative composition of the cut surface structure is almost the same, so priority criteria for comparative quality analysis are surface microgeometry parameters. The parameter evaluation shows high quality of cutting almost along the entire length of a cut, since the technological feature influence of plasma arc cut into the metal affects less than 0.3 mm from the sheet edge. The use of additional methods of gas-dynamic stabilization in PMVR-5.2 plasma torch (feed symmetry with a double swirl system of plasma-forming gas) makes it possible to achieve additional advantages in terms of surface quality compared to PMVR-5.1. A number of features that affects cut quality when cutting metals of different thicknesses for welding depends on the inclination angle of a plasma torch during cutting. Estimates of the surface layer hardness indicate minimal deviations from the requirements of GAZPROM Standard 2-2.4-083 (instructions on welding technologies in the construction and repair of field and main gas pipelines), which allows further use of cutting seams obtained by studied plasma torches for welding without removing thermal influence zones. Thus, the application of new plasma torches for precision-finishing plasma cutting of metals, including production of welded joints, is possible. © 2020, Allerton Press, Inc

Influence of Plasma Torch Design on Cutting Quality during Precision Air-Plasma Cutting of Metal

Abstract: Optical interferometry and metallographic analysis were used to study the structure of cutting seams obtained after 09G2S steel cutting by a PMVR-5 plasma torch. These plasma torches have many design features in the gas-dynamic stabilization system of the plasma arc. The application of a new plasma torch can obtain higher quality and lower energy costs of cutting medium-thick 09G2S steel. Metallographic analysis has shown that the qualitative composition of the cut surface structure is almost the same, so priority criteria for comparative quality analysis are surface microgeometry parameters. The parameter evaluation shows high quality of cutting almost along the entire length of a cut, since the technological feature influence of plasma arc cut into the metal affects less than 0.3 mm from the sheet edge. The use of additional methods of gas-dynamic stabilization in PMVR-5.2 plasma torch (feed symmetry with a double swirl system of plasma-forming gas) makes it possible to achieve additional advantages in terms of surface quality compared to PMVR-5.1. A number of features that affects cut quality when cutting metals of different thicknesses for welding depends on the inclination angle of a plasma torch during cutting. Estimates of the surface layer hardness indicate minimal deviations from the requirements of GAZPROM Standard 2-2.4-083 (instructions on welding technologies in the construction and repair of field and main gas pipelines), which allows further use of cutting seams obtained by studied plasma torches for welding without removing thermal influence zones. Thus, the application of new plasma torches for precision-finishing plasma cutting of metals, including production of welded joints, is possible. © 2020, Allerton Press, Inc

Investigation of systems for gas vortex stabilization of plasma torches

Several designs of plasma torches for cutting of metals are used to analyse the effect of design special features of the gas-air circuit on the efficiency of operation of the gas vortex stabilisation system. It is shown that the distribution of the flows of the plasma-forming gas in the cross section of the circuit is non-uniform. A method of stabilization by changing the dimensions of the expansion chamber is analysed. The main directions for further studies are outlined. © 2015 Taylor & Francis

Structural-functional principles of design in electric plasma technologies

The system features of functioning in electric plasma technologies (EPTs) are investigated. The principles of design, used in the process of designing plasma torches and EPTs, are generalized. Special attention is given to the need to take into account the conditions for the safe use of plasma torches. © 2013 © 2013 Taylor & Francis

Gas vortex stabilization in plasma torches: new solutions

The effect of different design solutions of the system of gas vortex stabilization of plasma torches for cutting of metals on the efficiency of equalization of the speed of the gas flows in the cross section of the gas circuit is analysed. The results of synthesis of the proposed solutions are used to design and optimize a new gas vortex system with a set of gas-dynamic filters. The advantages of using the new plasma torch with the modernized gas vortex stabilization system are indicated. © 2015 Taylor & Francis

Analysis of the acoustic safety of narrow-jet metal-cutting plasma torches

Two types of plasma torch for cutting of metals, working with narrow-jet (exact or constricted) plasma, are described. Methods of modernizing the plasma torches proposed taking into account the principles and design methods developed by the authors are outlined. The efficiency of design is analysed using acoustic safety criteria. The results of comparative analysis of the noise characteristics of Russian and foreign plasma torches for cutting in sound and ultrasonic noise emission ranges are presented. The advantages of the new narrow-jet plasma torch determined on the basis of the acoustic safety criterion in comparison with both the basic model and other investigated plasma torches are discussed. © 2016 Informa UK Limited, trading as Taylor & Francis Group

Investigation of systems for gas vortex stabilization of plasma torches

Several designs of plasma torches for cutting of metals are used to analyse the effect of design special features of the gas-air circuit on the efficiency of operation of the gas vortex stabilisation system. It is shown that the distribution of the flows of the plasma-forming gas in the cross section of the circuit is non-uniform. A method of stabilization by changing the dimensions of the expansion chamber is analysed. The main directions for further studies are outlined. © 2015 Taylor & Francis

Structural-functional principles of design in electric plasma technologies

The system features of functioning in electric plasma technologies (EPTs) are investigated. The principles of design, used in the process of designing plasma torches and EPTs, are generalized. Special attention is given to the need to take into account the conditions for the safe use of plasma torches. © 2013 © 2013 Taylor & Francis

Gas vortex stabilization in plasma torches: new solutions

The effect of different design solutions of the system of gas vortex stabilization of plasma torches for cutting of metals on the efficiency of equalization of the speed of the gas flows in the cross section of the gas circuit is analysed. The results of synthesis of the proposed solutions are used to design and optimize a new gas vortex system with a set of gas-dynamic filters. The advantages of using the new plasma torch with the modernized gas vortex stabilization system are indicated. © 2015 Taylor & Francis

Qualitative study of steel cutting with the use of the narrow jet plasma technology

By metallography and optical interferometry methods, the structure of 09G2S steel cutting seams fabricated with the use of narrow jet plasma technology is analyzed. The high quality of the seams allows welding without the removal of the heat-affected zones. The application of the new narrow jet plasma cutting technology provides high-quality welding seams, high efficiency of the process, and low energy consumption. © 2017, Pleiades Publishing, Ltd