Remoção da camada galvanizada por plasma

Abstract

The great difficulty in the process of recycling of galvanized steels is in the extraction of zinc. Thus, this work aims to obtain ideal parameters for the extraction of the zinc layer of a galvanized steel, using the vacuum plasma. API – 5L steel was used due to its aplication in the petroleum sector. The working gases during the process were hydrogen(H2), Argon (Ar) and a gaseous mixture of both gases in the same proportions, for a period of 3h and 5h in each configuration of gaseous atmosphere. X – Ray Fluorescence Spectroscopy (FRX), Microhardness and Optical Microscopy analyses were carried out to verify the efficiency of layer removel. The saple with H2 atmospheretreated for 3 hours presentedthe best results of the work, achieving an extraction of more than 50% of the zinc layer, showing that the parameters H2 with atmosphere are the starting point for total layer extration. In addition, it has been observed that there is a rearrangement of the outer layer to the internal of the tube, a phenomenon that is accentuated in the use of argon.