ANALISIS KEGAGALAN REL KERETA API AREA REJOSARI PT. KAI DIVRE IV PADA SAMBUNGAN LAS TERMIT
Railway failures have been found in the Rejosari area of PT. KAI Divre IV. The
initial of the failure is thought to have occurred in the filler metal portion of the
thermite welded profile. Statistics show that 75% of railway damage is caused by
the failure of thermite welds. Most of these failures occur due to low quality of
the weld results, such as coarse grain, inclusions, dendritic structure and
porosity. The quality of the welding results can impact the degradation of
ductility and toughness. Based on these problems, this study aims to determine
the main causes, mechanisms of railway failure and corrective steps that can be
taken to minimize the occurrence of failures. The tests carried out in this study
consisted of testing the micro and macro structures, testing the macro and
microhardness, chemical composition, and fractography. Inspection of
macroscopic fractography on the surface of the R.54 railway fault found a fault
pattern macroscopic cleavage, which indicates that the rail is experiencing
failure caused by brittle fracture. Macroscopic cleavage also shows that the
initial failure of the R.54 rail occurred in the rail body, to be precise, in the filler
metal area. Then the cracks spread following the direction of the fault pattern
macroscopic cleavage shaped like a river. Until the end of the fracture process,
the remaining material cannot withstand the loading given, so a fracture pattern is formed as a shear lip. The main cause of the initial formation of cracks cannot
be identified with certainty on the damaged R.54 rail. However, the results of
microstructural testing on thermit welding profiles at the head of the rail found
a lot of porosity. In addition, patterns such as mountains and valleys with sharp
edges were found in the welding area of the railway. Porosity and form factors
can cause stress concentrations that lead to the formation of the initial cracks.
Thus, the surface resulting from thermite welding and the quality of the welding
need to be improved. Like following welding procedure specification and
procedure qualification record as a classification template.
URI
https://repo.itera.ac.id/depan/submission/SB2306050045
Keyword