MICROHARDNESS AMENDMENT PROVIDED BY THE MASS, UTILITY MODEL MU8303487-0, IN STEEL PLATES ASTM-36
Pedro Rodrigues Lopes1; Gustavo Henrique Nazareno Fernandes1
1 Universidade Federal de Minas Gerais
doi:10.20906/CPS/COB-2015-1964
Resumo
The main objective of this work is to study the effects caused by the utility model MU8303487-0 developed and patented by the Laboratory of Robotics, Welding and Simulation of the Federal University of Minas Gerais. Many underwater welding studies indicates the difficulties of opening and stabilizing the welding electric arc, especially on the wet underwater welding. In order to solve this problem, it has been added the MU8303487-0 between the tip of three different types of electrodes and a metal plate. The MU8303487-0, due to its physic chemical characteristics, it is necessary to facilitate the process of dissociation and ionization, allowing the opening and establishment of the electrical arc. It was sought to know how and if this element interferes on the micro hardness of the metal plates. For this, weld seams with three different types of electrodes, 6013, 7018 and WW70 (Wet Welding) were performed, all submerged in water depth and hyperbaric tank at a pressure of 1 atm, simulating 10m depth to the bottom of the sea. The weld seams were made on plates of ASTM A36 steel and subsequently subjected to micro hardness analysis. It was observed that due to the diffusion process, the regions of the opening arc, exactly where MU8303487-0 were placed had an increase of the steel hardness, mainly associated with interstitial effect caused by manganese and other elements present in the compostition of the MU8303487-0.
Palavras-chave: underwater; microhardness; welding; UTILITY MODEL MU8303487-0