Corte a plasma e a jato de água abrasivo: comparação entre métodos e verificação da microestrutura em chapas de aço

Abstract

Currently, there are several forms of metal cuts on the market, such as laser cutting, plasma cutting, oxyfuel cutting, water jet cutting, among others. Each of these cutting processes has its specificities, so it is extremely important to be aware of these particular characteristics to ensure the choice of the most suitable method. In this work, the aim was to gain a better understanding of the processes of plasma and abrasive waterjet cutting, as well as the analysis of a material when submitted to these cutting processes. The material used was ASTM A36 steel which is a very common material in metallic structures in general. For the metallographic test, the procedures of cutting the specimen, embedding, sanding, polishing, chemical etching were carried out and, finally, the analysis by optical microscope to obtain the study data. The cold cut structures of the piece had almost completely ferritic grains with little pearlite, but in the plasma cut, where the cuts were made, there was a greater appearance of pearlite in the piece. From an economic point of view, in general terms, plasma stands out as it has a higher cutting speed, lower cost per part, but the ability of the abrasive waterjet to create such clean and precise cuts makes them indispensable for cuts that need these requests such as creating medical tools or small moving parts