THE AIR PLASMA CUTTING QUALITY OF SELECTED CONSTRUCTION MATERIALS

Abstract

Cutting is usually one of the initial and basic operations of the weldment manufacturing process. Thermal cutting, in particular plasma arc cutting is often used for the preparation of the production of welded structures. The plasma arc cutting process involves melting and ejecting the liquid metal from the cutting gap with a highly concentrated plasma electric arc which is generated between the non-consumable electrode and the workpiece. The paper presents the results of quality assessment of the air plasma cutting process of the selected construction materials – steel S960Q, steel S700QM, aluminum alloy 5754, copper M1E- with a thickness of 8 mm. The surface quality after cutting was assessed in accordance with ISO 9013 (perpendicularity or angularity tolerance, u; mean height of the profile, Rz 5µm). The bevel angle, the width of the cutting kerf and the diameter of the piercing hole. It has been shown that not only the quality parameters of the surface should be taken into account when assessing the quality of the surface after cutting. Important are also bevel angle, the method of piercing the sheet and the width of the cutting kerf at the top and bottom surfaces of the sheet. Taking into account the operational properties of elements after cutting, attention should be paid to the impact of cutting processes on structural and chemical changes caused by the effect of heat. The conducted research has shown the usefulness of the air plasma cutting process for all selected construction materials.