Search

This investigation presents the evaluation of AWS E 7018 coated electrodes based on the content of the peripheral coating components in order to improve their performance. Proportions for the coatings were estimated based on an McLean Anderson experimental design where the input variables are: X1- pyrolusite, X2- limestone+fluorite (for limestone: fluorite=1) and X3- FeCrMn. The homogenized blends were agglomerated with sodium silicate and water to form the pastes that were applied by immersion on the basic coating of the 3,2 mm diameter electrodes of the metal core. The isolines of the melting and deposition rates as well as the deposition efficiency and the bead geometry were generated for the evaluation of the electrodes. The results indicate that the composition of the coating with a better performance contributes to favorable changes compared to the electrode without peripheral coating as this increases the depth of the bead penetration, thus providing a narrower profile. [ABSTRACT FROM AUTHOR]

Based on the chemical composition of the manganese mineral, aluminum shaving and laminated rolled scale, a strategy is proposed to simultaneously produce ferromanganese and galaxite (abrasive material) by the application of aluminathermic reduction. The feasibility analysis of the aluminathermic process, bypassing the roasting stage of the pyrolusitic mineral, is carried out by assessing the enthalpies of the reaction of the pyrometallurgical mixtures. The evaluation of the technological feasibility of the process is completed both at lab scale and experimental pilot plant, in both cases they are obtained alloys with over 60% manganese and less than 0,1% carbon for industrial use. The chemical characterization of the slag guarantees their possible use as an abrasive material. [ABSTRACT FROM AUTHOR]