Analisis Variasi Flux Pada Proses Braze Welding Material Kuningan Terhadap Sifat Mekanik dan Struktur Mikro

Abstract

Propeller is an important component in ship propulsion systems. Ship propellers are
generally made of materials that are resistant to corrosion from seawater, such as brass.During their
use, propellers can sometimes experience damage due to collisions with coral, resulting in breakage,
erosion due to cavitation pressure, cracks, and bending. In the shipbuilding industry in Indonesia, the
braze welding method is commonly used for propeller repairs due to its relatively lower cost. One
essential part of the braze welding process is the use of flux. However, in reality, the use of flux is
sometimes replaced with borax, which does not meet the qualified standards. Therefore, this research
discusses the effect of various flux variations, including the use of field-used borax flux, standard
qualified FB3A flux, and a mixture of both, with 50% borax and 50% FB3A. The highest average tensile
strength was observed in the mixed flux variation at 251.11 MPa, while the lowest was in the borax
flux variation at 111.21 MPa. Similarly, the highest average impact value was found in the mixed flux
variation at 0.164 J/mm2, and the lowest was in the borax flux variation at 0.047 J/mm2. Microstructure
testing revealed two phases in this study, namely ? phase and ? phase.