PEMBUATAN FLEXIBLE COUPLING HYDRANT PIPE DIAMETER 4 INCH DARI BAHAN DUCTILE CAST IRON DENGAN PENGUJIAN TARIK, KEKERASAN, KOMPOSISI KIMIA DAN METALOGRAFI

Abstract

This flexible coupling is fabricated using the ductile cast iron material in a casting process. Casting is a process of melting a material and then molded it to suit the need. Flexible coupling is a device to join the pipe that provided with damper in a piping system.To know the quality of the ductile cast iron, the properties and micro structure of the material should be known. The testing to know this properties are hardness test, tensile test, and chemical composition and metallurgy. Ductile cast iron have a hardness 285 BHN, this value is bigger than the flexible coupling Victaulic type 75 which have 172,9 BHN in hardness.The tensile test have the value of 466,66 N/MM2, which is smaller than the mean value in hardness conversion that have the value of 898,98 MPA. This is caused by the imperfection in a cating of the specimen, for example air cavity defect. The tensile strength of ductile cast iron using the hardness conversion is bigger than the flexible coupling Victaulic type 75 which have 596,59 in hardness value. Keyword: Flexible coupling, ductile cast iron, micro structure, hardness, tensile test, chemical composition