The Influence of Calcite,Fluorite, and Rutile on the Fusion-Related Behavior of Metal Cored Coated Electrodes for Hardfacing

Coated electrodes for SMAW have exhibited their advantages for longer than one century. Means of boosting their performance, particularly for hardfacing, would be a raise in the alloying transfer efficiency and a lowering of the dilution with the substrate, without losing the production capacity. In this study, an evaluation about the operational behavior of a new conception of electrodes for hardfacing is described, i.e., metal cored coated electrodes. Experimental electrodes were produced using metal cored technique to obtain the rods. FeCrMn was used as alloying material at two grain sizes. Using the Mc Lean Anderson experimental design approach, the content ratio of CaCO₃:CaF₂:TiO₂ in the coating was varied. The effect of the coating composition and granulometry of the filling alloying material on the formation a cannon-like end was assessed. Fusion and metal transfer behaviors were evaluated through measurements of fusion and deposition rates, deposition efficiency, and duration and frequencies of short-circuiting. Based on a balance of performances, the most appropriate composition for the coating was determined. It was also observed that a coarser FeCrMn presented better performance.