Development of Surface Properties with In Situ TiB2 Intermetallic-Assisted Coating by Fe(18-X)Ti2BX (x=3,4,5)-Based Electrodes

In this study, Fe-Ti-B-based hardfacing electrodes were coated on a AISI 1010 steel substrate with the electric arc welding method. Using SEM, EDS, MAP and EBSD methods, the substrate-coating interface development of hardfacing alloys was investigated and it was determined that a highly compatible coating layer was formed with the substrate. It was observed that TiB2 phases, which have important contributions to the structure in the coating region, were formed as in situ and dispersed homogeneously in the microstructure. Hardness tests were carried out on the coating layers by different methods such as nano, micro and macro, and it was defined that the TiB2 phase had an average hardness of 3336.7 (+/- 27) Hv. In addition, it was specified that the eutectic structure of alpha + Fe2B formed with the increasing amount of boron in the system significantly contributes to the macro-hardness of the coating. According to the reciprocal wear test performed against Al2O3 abrasive ball, it was determined that the rate of wear decreases with the increasing amount of boron in the microstructure. However, it was observed that the friction coefficient decreases with the decreasing amount of boron in the microstructure. According to the potentiodynamic polarization test results performed in 3.5% NaCl solution, the potential values of the coating layers were more negative than the substrate material, while the current density values were understood to be lower than the substrate material. It was detected that the corrosion resistance of the coating layers increased with the increasing boron content in the electrode cover composition.